U.S. patent application number 17/445068 was filed with the patent office on 2021-12-02 for dispenser for firearm ammunition powder.
The applicant listed for this patent is AOB Products Company. Invention is credited to Justin Burke, Dennis Cauley, Mike Cottrell, Mark Dalton, James Gianladis, Matthew Kinamore, Tim Kinney, Kyle Martin, Michael Poehlman, Brian Steere, Jeff Talbott, James Tayon, Anthony Vesich, Joel Yuodsnukis.
Application Number | 20210372756 17/445068 |
Document ID | / |
Family ID | 1000005779228 |
Filed Date | 2021-12-02 |
United States Patent
Application |
20210372756 |
Kind Code |
A1 |
Kinney; Tim ; et
al. |
December 2, 2021 |
DISPENSER FOR FIREARM AMMUNITION POWDER
Abstract
A dispenser for dispensing powder for firearm ammunition and
associated methods. The dispenser can include a hopper, a conveyor,
a scale, a dispenser controller, and a tangible storage medium
storing instructions executable by the dispenser controller. The
dispenser controller can execute a powder calibration sequence
and/or a dispensing sequence. In the powder calibration sequence
and/or the dispensing sequence, the dispenser controller desirably
learns the dispense rate of the powder and uses the dispense rate
to optimize dispensing of the powder and increase precision in
dispensing a target mass of powder. The conveyor can comprise a
conveyor tube having a conveyor tube axis oriented to extend at an
upward angle with respect to horizontal.
Inventors: |
Kinney; Tim; (Warrenton,
MO) ; Tayon; James; (Moberly, MO) ; Cottrell;
Mike; (Ashland, MO) ; Cauley; Dennis;
(Fayette, MO) ; Burke; Justin; (Columbia, MO)
; Steere; Brian; (Columbia, MO) ; Martin;
Kyle; (Columbia, MO) ; Vesich; Anthony;
(Columbia, MO) ; Poehlman; Michael; (Columbia,
MO) ; Gianladis; James; (Harrisburg, MO) ;
Kinamore; Matthew; (Columbia, MO) ; Yuodsnukis;
Joel; (Columbia, MO) ; Talbott; Jeff;
(Florissant, MO) ; Dalton; Mark; (Columbia,
MO) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
AOB Products Company |
Columbia |
MO |
US |
|
|
Family ID: |
1000005779228 |
Appl. No.: |
17/445068 |
Filed: |
August 13, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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16107486 |
Aug 21, 2018 |
11118884 |
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17445068 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F42B 33/0207 20130101;
F42B 33/0285 20130101 |
International
Class: |
F42B 33/02 20060101
F42B033/02 |
Claims
1. A dispenser for dispensing powder for firearm ammunition, the
dispenser comprising: a base configured to rest on a support
surface; a scale supported by the base, the scale including a scale
platform and a scale sensor, the scale sensor positioned and
configured to generate a scale signal in response to powder
supported by the platform; a hopper supported by the base and
configured to hold a supply of powder; a conveyor supported by the
base and arranged to dispense powder from the hopper to the scale;
a powder dispenser controller configured to receive the scale
signal, the powder dispenser controller operable to control the
conveyor to dispense powder to the scale; and a tangible storage
medium storing powder dispenser controller executable dispensing
instructions that, when executed by the powder dispenser
controller: run the conveyor at a conveyor speed to dispense powder
for a dispensing cycle, during the dispensing cycle while the
conveyor is dispensing powder, determine an actual dispense rate of
powder dispensed to the scale during the dispensing cycle based on
the scale signal, based on the actual dispense rate of the powder
dispensed to the scale during the dispensing cycle, change the
conveyor speed during the dispensing cycle or change a dispensing
cycle run end time at which the conveyor is to be stopped for
ending the dispensing cycle, and stop running the conveyor at the
dispensing cycle run end time.
2. A dispenser as set forth in claim 1, wherein the tangible
storage medium stores powder dispenser controller executable
instructions to monitor the actual dispense rate by repeatedly
determining, at different times during the dispensing cycle as the
conveyor is dispensing powder, the actual dispense rate of powder
dispensed during the dispensing cycle, and to repeatedly change the
conveyor speed during the dispensing cycle or repeatedly change the
dispensing cycle run end time before reaching the dispensing cycle
run end time.
3. A dispenser as set forth in claim 1, wherein the tangible
storage medium stores powder dispenser controller executable
instructions to determine, at different times during the dispensing
cycle as the conveyor is dispensing powder, a mass of powder
supported by the scale based on the scale signal to determine the
actual dispense rate of powder.
4. A dispenser as set forth in claim 1, further comprising a user
interface adapted to receive user input representative of a target
mass of powder to be dispensed to the scale and to generate a
target mass signal based on the received user input, the tangible
storage medium comprising powder dispenser controller executable
instructions to stop running the conveyor at the dispensing cycle
run end time based on the target mass signal.
5. A dispenser for dispensing powder for firearm ammunition, the
dispenser comprising: a base configured to rest on a support
surface; a scale supported by the base, the scale including a scale
platform and a scale sensor, the scale sensor positioned and
configured to generate a scale signal in response to powder
supported by the platform; a hopper supported by the base and
configured to hold a supply of powder; a conveyor supported by the
base and arranged to dispense powder from the hopper to the scale;
a user interface adapted to receive user input representative of a
target mass of powder to be dispensed to the scale and to generate
a target mass signal based on the received user input; a powder
dispenser controller configured to receive the scale signal and the
target mass signal, the powder dispenser controller operable to
control the conveyor to dispense powder to the scale; and a
tangible storage medium storing powder dispenser controller
executable calibration instructions that, when executed by the
powder dispenser controller: run the conveyor at a conveyor speed
to dispense powder to the scale for a powder calibration cycle,
determine a dispense rate at which powder was dispensed to the
scale during the powder calibration cycle, after the powder
calibration cycle, run the conveyor at the conveyor speed for a
dispensing cycle, and stop running the conveyor to end the
dispensing cycle at a dispensing cycle run end time that is based
on the dispense rate and the target mass signal.
6. A dispenser as set forth in claim 5, wherein the tangible
storage medium stores powder dispenser controller executable
instructions to determine, before operating the conveyor for the
dispensing cycle, whether the dispense rate is in a target dispense
rate range stored by the tangible storage medium, and to operate
the conveyor at the dispense speed for the dispensing cycle if the
dispense rate is in the target dispense rate range.
7. A dispenser as set forth in claim 5, wherein the dispense speed
is a first dispense speed, the powder calibration cycle is a first
powder calibration cycle, the dispense rate is a first dispense
rate, and the tangible storage medium stores powder dispenser
executable calibration instructions to run the conveyor at a second
dispense speed less than the first dispense speed to dispense
powder to the scale for a second powder calibration cycle, and to
determine a second dispense rate at which the powder was dispensed
to the scale during the second powder calibration cycle.
8. A dispenser as set forth in claim 7, wherein the dispensing
cycle is a first dispensing cycle, the dispensing cycle run end
time is a first dispensing cycle run end time, and the tangible
storage medium stores powder dispenser executable dispensing
instructions to determine a second dispensing cycle run end time
based on the target mass signal and the second dispense rate, and
to operate the conveyor at the second dispense speed for a second
dispensing cycle until the second dispensing cycle stop time.
9. A dispenser as set forth in claim 8, wherein the tangible
storage medium stores powder dispenser executable calibration
instructions to run the conveyor at a third dispense speed less
than the second dispense speed to dispense powder to the scale for
a third powder calibration cycle, and to determine a third dispense
rate at which the powder was dispensed to the scale during the
third powder calibration cycle.
10. A dispenser as set forth in claim 9, wherein the tangible
storage medium stores powder dispenser executable dispensing
instructions to determine a third dispensing cycle run end time
based on the target mass signal and the third dispense rate, and to
operate the conveyor at the third dispense speed for a third
dispensing cycle until the third dispensing cycle run end time.
11. A dispenser as set forth in claim 8, wherein the tangible
storage medium stores powder dispenser controller executable
dispensing instructions to intermittently operate the conveyor for
a third dispensing cycle until the powder dispenser controller
detects the target mass of powder supported by the scale platform
based on the scale signal.
12. A dispenser as set forth in claim 5, wherein the conveyor speed
is a first conveyor speed and the dispensing cycle is a first
dispensing cycle, and the tangible storage medium stores powder
dispenser controller executable dispensing instructions to
intermittently operate the conveyor at a conveyor speed less than
the first conveyor speed for a second dispensing cycle until the
powder dispenser controller detects the target mass of powder
supported by the scale platform based on the scale signal.
13. A dispenser as set forth in claim 5, wherein the dispense rate
is a first dispense rate and the tangible storage medium stores
powder dispenser controller executable instructions to determine,
during the dispensing cycle as the conveyor is dispensing powder, a
second dispense rate of powder dispensed during the dispensing
cycle, and to change the dispensing cycle run end time during the
dispensing cycle based on the second dispense rate.
14. A dispenser as set forth in claim 13, wherein the tangible
storage medium stores powder dispenser controller executable
instructions to repeatedly determine, at different times during the
dispensing cycle as the conveyor is dispensing powder, a mass of
powder supported by the scale, and to determine the second dispense
rate based on the determined mass of powder.
15. A dispenser as set forth in claim 13, wherein the tangible
storage medium stores powder dispenser controller executable
instructions to monitor the second dispense rate by repeatedly
determining, at different times during the dispensing cycle as the
conveyor is dispensing powder, the second dispense rate of powder
dispensed during the dispensing cycle, and to repeatedly change the
dispensing cycle run end time based on the second dispense
rate.
16. A dispenser for dispensing powder for firearm ammunition, the
dispenser comprising: a base configured to rest on a support
surface; a scale supported by the base, the scale including a scale
platform and a scale sensor, the scale sensor positioned and
configured to generate a scale signal in response to powder
supported by the platform; a hopper supported by the base and
configured to hold a supply of powder; a conveyor supported by the
base and arranged to dispense powder from the hopper to the scale;
a powder dispenser controller configured to receive the scale
signal, the powder dispenser controller operable to control the
conveyor to dispense powder from the hopper to the scale; and a
tangible storage medium storing powder dispenser controller
executable instructions that, when executed by the powder dispenser
controller: run the conveyor to dispense a first amount of powder
to the scale, determine a dispense rate at which the first amount
of powder was dispensed to the scale, and after dispensing the
first amount of powder to the scale, run the conveyor, at a
conveyor speed based on said determined dispense rate or until a
dispensing cycle run end time based on said determined dispense
rate, to dispense a second amount of powder to the scale.
17. A dispenser as set forth in claim 16, wherein tangible storage
medium stores powder dispenser executable instructions to, after
dispensing the first amount of powder to the scale, run the
conveyor at the conveyor speed based on the determined dispense
rate to dispense the second amount of powder to the scale.
18. A dispenser as set forth in claim 16, wherein the tangible
storage medium stores powder dispenser executable instructions to,
after dispensing the first amount of powder to the scale, run the
conveyor until the dispensing cycle run end time based on the
determined dispense rate to dispense the second amount of powder to
the scale.
19. A dispenser as set forth in claim 16, wherein the tangible
storage medium stores powder dispenser controller executable
instructions to continuously run the conveyor from dispensing the
first amount of powder to dispensing the second amount of
powder.
20. A dispenser for dispensing powder for firearm ammunition, the
dispenser comprising: a base configured to rest on a horizontal
support surface; a scale supported by the base; a hopper supported
by the base and configured to hold a supply of powder; and a
conveyor tube supported by the base and rotatable about a conveyor
tube axis to dispense powder from the hopper to the scale, the
conveyor tube arranged with respect to the base such that the
conveyor tube axis extends distally from the hopper at an upward
angle when the base is resting on the horizontal support surface.
Description
FIELD
[0001] The present disclosure generally relates to dispensing
apparatus, and more particularly to a dispenser for dispensing
powder for firearm ammunition.
BACKGROUND
[0002] Persons manufacturing or reloading firearm ammunition often
use electronic powder dispensers to dispense portions of powder to
be used as a propellant in a round of ammunition. Such electronic
powder dispensers are typically used to dispense a certain amount
of powder to a tray, and the powder is then poured into a case or
shell for making the round of ammunition. Usually, the powder
dispensers are used to dispense a plurality of loads of powder, one
after another, for loading many rounds of ammunition. Common
electronic powder dispensers suffer from various disadvantages. For
example, some electronic powder dispensers dispense powder
relatively slowly to avoid overshooting the desired final mass of
powder. Slow operation can cause user dissatisfaction due to the
overall length of time required to dispense powder for multiple
rounds of ammunition. Some electronic powder dispensers do not
reliably dispense exactly the target mass of powder, which also
causes user dissatisfaction.
SUMMARY
[0003] In one aspect, a dispenser for dispensing powder for firearm
ammunition includes a base configured to rest on a support surface.
The dispenser includes a scale supported by the base. The scale
includes a scale platform and a scale sensor. The scale sensor is
positioned and configured to generate a scale signal in response to
powder supported by the platform. A hopper is supported by the base
and configured to hold a supply of powder. A conveyor is supported
by the base and arranged to dispense powder from the hopper to the
scale. A powder dispenser controller is configured to receive the
scale signal. The powder dispenser controller is operable to
control the conveyor to dispense powder to the scale. A tangible
storage medium stores powder dispenser controller executable
dispensing instructions that, when executed by the powder dispenser
controller: run the conveyor at a conveyor speed to dispense powder
for a dispensing cycle; during the dispensing cycle while the
conveyor is dispensing powder, determine an actual dispense rate of
powder dispensed to the scale during the dispensing cycle based on
the scale signal; based on the actual dispense rate of the powder
dispensed to the scale during the dispensing cycle, change the
conveyor speed during the dispensing cycle or change a dispensing
cycle run end time at which the conveyor is to be stopped for
ending the dispensing cycle, and stop running the conveyor at the
dispensing cycle run end time.
[0004] In another aspect, a dispenser for dispensing powder for
firearm ammunition includes a base configured to rest on a support
surface. The dispenser includes a scale supported by the base. The
scale includes a scale platform and a scale sensor. The scale
sensor is positioned and configured to generate a scale signal in
response to powder supported by the platform. A hopper is supported
by the base and configured to hold a supply of powder. A conveyor
is supported by the base and arranged to dispense powder from the
hopper to the scale. A user interface is adapted to receive user
input representative of a target mass of powder to be dispensed to
the scale and to generate a target mass signal based on the
received user input. A powder dispenser controller is configured to
receive the scale signal and the target mass signal, the powder
dispenser controller operable to control the conveyor to dispense
powder to the scale. A tangible storage medium stores powder
dispenser controller executable calibration instructions that, when
executed by the powder dispenser controller: run the conveyor at a
conveyor speed to dispense powder to the scale for a powder
calibration cycle; determine a dispense rate at which powder was
dispensed to the scale during the powder calibration cycle; after
the powder calibration cycle, run the conveyor at the conveyor
speed for a dispensing cycle; and stop running the conveyor to end
the dispensing cycle at a dispensing cycle run end time that is
based on the dispense rate and the target mass signal.
[0005] In another aspect, a dispenser for dispensing powder for
firearm ammunition includes a base configured to rest on a support
surface. The dispenser includes a scale supported by the base. The
scale includes a scale platform and a scale sensor. The scale
sensor is positioned and configured to generate a scale signal in
response to powder supported by the platform. A hopper is supported
by the base and configured to hold a supply of powder. A conveyor
is supported by the base and arranged to dispense powder from the
hopper to the scale. A powder dispenser controller is configured to
receive the scale signal. The powder dispenser controller is
operable to control the conveyor to dispense powder from the hopper
to the scale. A tangible storage medium stores powder dispenser
controller executable instructions that, when executed by the
powder dispenser controller: run the conveyor to dispense a first
amount of powder to the scale; determine a dispense rate at which
the first amount of powder was dispensed to the scale; and after
dispensing the first amount of powder to the scale, run the
conveyor, at a conveyor speed based on said determined dispense
rate or until a dispensing cycle run end time based on said
determined dispense rate, to dispense a second amount of powder to
the scale.
[0006] In yet another aspect, a dispenser for dispensing powder for
firearm ammunition includes a base configured to rest on a
horizontal support surface. The dispenser includes a scale
supported by the base. A hopper supported by the base is configured
to hold a supply of powder. A conveyor tube supported by the base
is rotatable about a conveyor tube axis to dispense powder from the
hopper to the scale. The conveyor tube is arranged with respect to
the base such that the conveyor tube axis extends distally from the
hopper at an upward angle when the base is resting on the
horizontal support surface.
[0007] Other objects and features of the present disclosure will be
in part apparent and in part pointed out herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a perspective of a powder dispenser of the present
disclosure;
[0009] FIG. 2 is a section of the powder dispenser taken in a plane
including line 2-2 of FIG. 1;
[0010] FIG. 3 is a fragmentary section of the powder dispenser
taken in a plane including line 3-3 of FIG. 1;
[0011] FIG. 4 is a fragmentary section of the powder dispenser
taken in a plane including line 4-4 of FIG. 1;
[0012] FIG. 5 is a schematic showing electronic components of the
powder dispenser;
[0013] FIG. 6 is a fragmentary top view of the dispenser showing a
user interface of the dispenser;
[0014] FIGS. 7A-7C are flow charts of a calibration algorithm for
execution by the powder dispenser; and
[0015] FIGS. 8A-8E are flow charts of a powder dispensing algorithm
for execution by the powder dispenser.
[0016] Corresponding reference characters indicate corresponding
parts throughout the drawings.
DETAILED DESCRIPTION
[0017] Referring to FIGS. 1-6, a powder dispenser of the present
disclosure is designated generally by the reference number 10. The
dispenser 10 is configured to dispense precise amounts of powder
(e.g., gun powder or propellant powder) for use in ammunition
loading or other purposes. In general, the dispenser 10 includes a
housing 12, a hopper 14, a conveyor 16, a scale 18, and a user
interface 20. The hopper 14 is configured to hold a supply of
powder to be dispensed in numerous discharges of powder of precise
quantity. The conveyor 16 is arranged to receive powder from the
hopper 14 and to dispense the powder to the scale 18. The scale
measures the amount of powder supported by the scale. A tray 22 or
other container can be supported by the scale 18 for receiving and
containing the dispensed amount of powder. The user interface 20 is
configured to receive user input and to display information
associated with the powder dispenser 10, such as a target amount of
powder to be dispensed and/or a mass of powder currently supported
by the scale. Components of the dispenser 10 can be made of
plastic, metal, and/or other suitable materials.
[0018] In one example, the dispenser 10 may be used to dispense a
small amount of powder for use in a single round of ammunition. The
dispenser 10 can be operated repeatedly to dispense the same amount
of powder for use in manufacturing or reloading several rounds of
ammunition of the same type. For safety and accuracy when shooting
the rounds, it is important that the amounts of powder be precisely
measured and be consistent from round to round for a given type of
ammunition. Powder dispensing is complicated by the fact that
different types of powders have different flow characteristics
caused by attributes such as shape and size of the granules of the
powder. Common types of powders include extruded, flake, and ball
powders. Ball powder flows relatively freely, and flake powder may
flow as freely as ball powder. Extruded powder usually flows less
freely compared to ball and flake powder. Dispense rate of the
powder can also vary based on the amount of powder in the hopper 14
(more powder, more down pressure) and the moisture content of the
powder. The amount of powder dispensed can exceed the desired
amount if the powder flows more quickly than expected, especially
when a fast conveyor speed is used.
[0019] The dispenser 10 is constructed to enable a user to dispense
powder quickly and in precise amounts notwithstanding the type of
powder being dispensed and notwithstanding other factors such as
the amount of powder in the hopper 14 or the moisture content of
the powder. The dispenser 10 automatically adapts to powders having
different flow characteristics to optimize the dispensing process.
For example, as explained in further detail below, in a calibration
mode and/or in a dispensing mode, the dispenser 10 can learn the
dispense rate of a powder and use the learned dispense rate to set
a time to stop running the conveyor 16 when a certain amount of
powder is predicted to have been dispensed. When operating the
conveyor 16 at fast speeds, if the conveyor were stopped when the
scale 18 indicates the desired amount of powder has been dispensed,
over dispensing would likely result due to lag in scale feedback,
inertia of the conveyor, and/or flow characteristics of the powder.
The ability of the dispenser 10 to automatically and dynamically
adjust in real time based on the learned dispense rate of the
powder enables the dispenser to more reliably dispense precise
amounts of powder with the conveyor 16 operating at a relatively
fast speed, leading to increased user satisfaction.
[0020] Referring now to FIGS. 1 and 2, the dispenser housing 12
includes a base 12A and an upper portion 12B extending upward from
the base. The base 12A includes four feet 12C positioned for
engagement with a support surface such as a table top or bench top.
The feet 12C are adjustable in height for leveling the scale 18 in
a horizontal orientation such that an upper face 18A of a scale
platform 18B is horizontal. The housing 12 is constructed to house
various electronic components of the dispenser 10 and supports the
hopper 14, conveyor 16, scale 18, and user interface 20. Other
types of housings can be used without departing from the scope of
the present invention.
[0021] The hopper 14 includes a generally cylindrical container 14A
having a lid 14B. The lid 14B can be removed from the container 14A
for loading powder in the hopper 14. The container 14A is received
in a well in the upper portion 12B of the housing 12. The container
14A has an interior that together with the well of the upper
portion 12B of the housing 12 forms a powder compartment 26 for
receiving and holding powder. Thus, in the illustrated embodiment,
the hopper 14 is formed by not only the cylindrical container 14A
but also the upper portion 12B of the housing 12. As shown in FIGS.
2 and 3, the well in the housing 12 is tapered to provide a
relatively narrow lower end of the powder compartment 26. The
bottom end of the powder compartment 26 is open to a chute 28 for
emptying powder from the hopper 14. A bottom end of the chute 28 is
normally closed by a cap 30 and can be opened to permit powder to
flow out of the chute for emptying the hopper 14.
[0022] In the illustrated embodiment, the conveyor 16 comprises a
conveyor tube extending through the lower end of the powder
compartment 26 for receiving powder from the powder compartment and
conveying the powder to the scale 18. The conveyor tube 16 has a
proximal end receiving a fitting 32 that connects the conveyor tube
to a motor 34. For example, the motor can be a 12 volt motor. The
motor 34 is supported by the housing 12 and has a motor shaft 34A
received in and conjointly rotatable with the fitting 32. The
conveyor tube 16 extends through two bearings 38 supported by the
housing 12 to support the conveyor tube for rotation about a
conveyor tube axis A1. A portion of the conveyor tube 16 between
the two bearings 38 is exposed in the powder compartment 26 and has
a plurality of openings 16A (e.g., three openings) for powder to
enter the interior of the conveyor tube. The conveyor tube 16 can
be rotated by the motor 34 about the conveyor tube axis A1 to
receive powder through the openings 16A, to convey powder distally
along the interior of the tube, and to dispense powder from a
distal open end of the tube. The illustrated conveyor tube 16 has
internal grooves and ridges extending along the length of the tube
parallel to the axis A1 to promote conveyance of powder along the
tube as the tube is rotated. However, the inside of the tube can be
smooth walled or have other flow features (e.g., helical rifling)
without departing from the scope of the present invention. The
motor 34 is operable at different speeds to run the conveyor 16 at
different speeds (e.g., measured by rotations per second or radians
per second about the conveyor axis). The conveyor speed can also be
referenced in terms of a duty cycle of the motor 34. Other types of
conveyors and systems for moving the conveyor 16 can be used
without departing from the scope of the present invention.
[0023] Referring to FIGS. 2, and 4, the scale 18 includes the scale
platform 18B and a scale sensor 40. The scale platform 18B includes
the upper face 18A, which is sized and shaped to support a powder
container such as the illustrated tray 22. Inside the housing 12,
the scale 18 includes a first cantilevered beam 42 supporting the
platform 18B. As shown in FIG. 4, the first beam 42 includes an end
connected to the platform 18B and another end connected to a second
cantilevered beam 44 by fasteners 46 (e.g., two screws). The second
beam 44 is secured at its opposite end to the housing 12 by
additional fasteners 48. The second beam 44 has a generally dog
bone shaped opening 44A providing relatively thin beam portions 44B
where four strain gauges 50 are applied to the second beam in a
Wheatstone configuration. The combination of the group of strain
gauges 50 and the beam 44 forms a load cell. The strain gauges 50
indicate a changed resistance value (scale signal) in response to
flexure of the beam 44 proportional to the load on the scale
platform 18B transferred to the load cell via the first beam 42.
The load cell acts as the scale sensor 40 for sensing an amount of
powder supported by the scale 18 and produces a corresponding scale
signal. Other types of scale sensors, such as other types of load
cells (e.g., having beams of other shapes or sizes, and/or having
other numbers or arrangements of strain gauges), can be used
without departing from the scope of the present invention.
Referring to FIG. 2, the first beam 42 includes forward and
rearward arms 42A, 42B arranged to contact upper ends of posts 52
inside the housing 12 to define maximum downward travel of the
scale platform 18B relative to the housing.
[0024] In one aspect of the present disclosure, the conveyor tube
16 is supported by the housing 12 so the conveyor tube axis A1
extends distally away from the hopper 14 at an upward angle .alpha.
with respect to horizontal when the face 18A of the scale platform
18B is horizontal. For example, the angle .alpha. can be in the
inclusive range of 0 to 15 degrees, more desirably, 0.5 to 3
degrees, and in one embodiment is about 1 degree. This is different
from known electronic dispensers having conveyor tubes that extend
distally away from a hopper at a downward angle with respect to
horizontal. The upward angle .alpha.1 of the tube 16 assists in
preventing unwanted over dispensing of powder due to a powder being
particularly free flowing. The advantage of the upward angled
conveyor tube 16 can be appreciated by considering an extreme
hypothetical case in which a powder flows as freely as water, such
that as soon as the powder enters the conveyor tube from the hopper
14, the powder would flow through the conveyor tube and exit the
distal end even if the conveyor is not operating. The upward angle
of the conveyor tube 16 increases resistance to powder flow through
the conveyor tube to minimize the effect of gravity in causing
freely flowing powder to over dispense. In other words, the upward
angle of the conveyor tube 16 assists in limiting powder dispensing
to only the time during which the conveyor tube is rotating such
that the dispenser 10 can more precisely control dispensing of
powder to meet a target dispensing amount.
[0025] As shown schematically in FIG. 5, a control system 60 of the
dispenser 10 includes a dispenser controller 62 (e.g.,
microprocessor or central processing unit), a non-transitory
tangible storage medium 64 (e.g., including forms of storage such
as software and/or firmware), and the user interface 20 including a
user input 66 and a display 68. A power source 70 such as batteries
or a power cord can be used for providing electrical power to the
control system. The control system 60 includes interconnection
electronics 71 (e.g., including electrical, fiber optic lines,
and/or wireless communication devices) that operatively connect the
various components of the control system with each other and with
other components of the dispenser 10. For example, the dispenser
controller 62 can receive the scale signals and user input signals
via the interconnection electronics 71. It will be appreciated that
the interconnection electronics 71 can include other components,
such as A/D converters and/or filters through which signals such as
the scale signal passes to the dispenser controller 62.
[0026] As shown in FIG. 2, a printed circuit board assembly 72 in
the housing 12 can be configured to include the dispenser
controller 62 and the storage medium 64. The dispenser controller
62 is configured to read and execute instructions stored in the
storage medium 64, and is responsive to the user input 66, for
controlling operation of the dispenser 10. A user can enter and/or
modify instructions stored on the storage medium 64 via the user
input 66. In the illustrated embodiment, as shown in FIG. 6, the
user interface 20 comprises a touch screen, described in further
detail below. Other types of user interfaces can be used without
departing from the present invention. The user interface 20
provides command signals via the interconnection electronics 71 to
the dispenser controller 62. The command signals (e.g., target mass
signal) can include changes to data (e.g., target mass of powder to
be dispensed) stored in the tangible storage medium 64. The
dispenser controller 62 responds to the command signals and
provides control signals corresponding thereto via the
interconnection electronics 71 to the conveyor. It will be
appreciated that in other embodiments the dispenser controller 62
and/or the tangible storage medium 64 can be part of another device
such as a smart phone or tablet operatively connectable to the
conveyor 16 and scale 18 (e.g., wirelessly) without departing from
the scope of the present invention.
[0027] Referring to FIG. 6, in the illustrated embodiment, the user
interface 20 comprises a touch screen, including both a user input
66 and a display 68. The display 68 includes a liquid crystal
display screen, and the user input 66 can include a touch-sensitive
panel on the display screen. The display 68 includes a first
numerical display 68A for displaying a mass of powder currently
supported by the scale 18. The display 68 includes a second
numerical display 68B for displaying a target amount of powder to
be dispensed. The user input 66 includes actuators at various areas
of the touch screen where the touch screen is responsive to the
touch of a user. The actuators may be identifiable to the user by
text or graphic information on the display 68 at respective areas
of the touch sensitive panel. The user input 66 includes actuators
arranged as a number pad 80 adapted for receiving user input such
as a target mass of powder to be dispensed, which results in a
target mass signal sent to the dispenser controller 62. The user
input 66 includes a CAL actuator 82 for performing a calibration of
the scale 18 during which the user supports two weights 83 (FIG. 1)
of known mass (e.g., 50 grams each) on the scale platform 18B to
calibrate the scale. The user input 66 includes a POWDER CAL
actuator 84 for implementing a powder calibration sequence,
described below, during which the dispenser 10 learns flow
characteristics of a powder to be dispensed. A MODE actuator 86
permits the user to select among different modes, such as a manual
dispensing mode and an automatic dispensing mode. A UNITS actuator
88 is provided for changing between grains and grams. A ZERO
actuator 90 is provided for zeroing or taring the scale 18 (e.g.,
to account for the tray 22 supported on the scale platform 18B). A
TRICKLE actuator 92 permits the user to manually trickle powder
from the conveyor 16 to the scale 18. The user input 66 also
includes other actuators, including an on/off actuator 94 and an
execute actuator 96, which are not part of the touch screen. Other
types of user interfaces can be used without departing from the
scope of the present invention. For example, the display 68 and
user input 66 can be separate from one another. The display 68 can
include other types of screens or indicators. Moreover, the user
input 66 can comprise other types of actuators, such as keyboards,
mice, buttons, switches, or even microphones for receiving
information from the user.
[0028] Example operations of the dispenser 10 will now be described
with respect to FIGS. 7A-8E. As outlined in FIGS. 7A-7C, an initial
step the user may choose to execute is a powder calibration
sequence 100 during which the dispenser 10 in a powder calibration
mode executes one or more powder calibration cycles. As explained
below, goals of the powder calibration sequence 100 are to learn
dispense rates of the powder at different conveyor speeds and to
set dispensing parameters (e.g., conveyor speeds for calibrated
dispense rates) so subsequent dispensing of the powder can be
accurate. After the powder calibration sequence, in a dispensing
mode (outlined in FIGS. 8A-8E) the user can execute a dispensing
sequence 102 to dispense a target amount of powder. The dispensing
sequence 102 can include one or more dispensing cycles in which the
conveyor 16 operates at different speeds (e.g., stepped down
speeds) to optimize quickness of dispensing without sacrificing
dispensing precision. During a dispensing cycle, the dispenser 10
desirably monitors dispensing characteristics (e.g., real time
dispense rate) and sets dispensing parameters (e.g., conveyor run
end time) to further optimize quickness and precision of
dispensing. Optionally, the powder calibration sequence 100 can be
skipped by proceeding directly to a dispensing sequence 102.
[0029] When powder has been loaded into the hopper 14, a powder
calibration sequence 100 can be initiated by pressing the POWDER
CAL actuator 84. The dispenser 10 executes a series of powder
calibration cycles to determine a dispense rate of the powder at
different conveyor speeds in preparation for a later dispensing
sequence 102. The first step in the calibration sequence 100 is to
prime 104 the dispenser 10 by turning the conveyor tube 16 for a
preset time, such as 4 seconds. This causes powder from the hopper
14 to enter the conveyor tube 16 through the openings 16A, to
substantially fill the conveyor tube, and to begin falling out of
the open distal end of the conveyor tube. Accordingly, powder in
the conveyor tube 16 is ready to be immediately dispensed when the
conveyor tube begins turning again. The powder dispensed during
priming can be removed from the tray 22 or the scale 18 can be
tared. Alternatively, the powder from priming can remain in the
tray 22 and the dispenser can use that mass as its 0 point.
[0030] The dispenser 10 then proceeds to calibrate 106 for a first
dispense rate. For example, the first dispense rate can be a
relatively fast rate. The tangible storage medium 64 stores a
default speed at which to operate the conveyor 16 for the fast
dispense rate. The default speed can be stored in terms of a duty
cycle or voltage for the motor 34 for turning the conveyor tube.
For example, the stored value can be 60% duty cycle, which would be
the equivalent of 7.2 volts for the 12 volt motor. The conveyor 16
operates 108 at this speed for a default time, such as 4 seconds.
The conveyor 16 stops and the dispenser controller 62 waits for the
scale reading to stabilize. After weighing 110 the powder
dispensed, the dispenser controller 62 calculates 112 the dispense
rate of the powder dispensed for the 4 seconds (mass divided by
time). By comparing 114 the calculated dispense rate with a range
of dispense rates stored in the tangible storage medium 64, the
dispenser controller 62 determines whether the calculated dispense
rate is greater than desired or less than desired. The desired
dispense rate can be stored as a preset range such as the range of
4 to 6 grains per second. If the calculated dispense rate is
greater than desired, the dispenser controller 62 conducts 116
another calibration cycle at a conveyor speed less than the
previous conveyor speed. For example, the motor 34 may be operated
at 55% duty cycle (dispensing parameter) instead of 60% duty cycle.
On the other hand, if the calculated dispense rate is less than the
desired dispense rate, the dispenser controller 62 conducts 118
another calibration cycle at a conveyor speed greater than the
previous conveyor speed, such as 65% instead of 60% duty cycle.
This process is repeated if necessary until the resulting dispense
rate is within the desired range. The duty cycle (broadly,
dispensing parameter) used to achieve the calibrated fast dispense
rate is saved 120 to the tangible storage medium 64 for later use
in the dispensing mode.
[0031] Referring to FIG. 7B, after calibrating for the fast
dispense rate, the powder calibration sequence continues with
calibration for a second dispense rate 122. For example, the second
dispense rate can be less than the first dispense rate and will be
referred to as a medium dispense rate. The conveyor 16 is operated
124 for a preset time (e.g., 4 seconds) at a preset default
conveyor speed, such as a motor duty cycle of 35%. When the
conveyor 16 stops, the scale 18 is permitted to stabilize, the
amount of powder dispensed is weighed 126, and the dispense rate is
determined 128. The dispenser controller 62 compares 130 the
calculated dispense rate with a preset desired dispense rate, which
can be the range of 1.5 to 3 grains per second. If the calculated
dispense rate exceeds the desired dispense rate, the calibration
cycle is repeated 132 at a slower conveyor speed (e.g., 30% duty
cycle). If the calculated dispense rate is less than the desired
dispense rate, the calibration cycle is repeated 134 at a faster
conveyor speed (e.g., 40% duty cycle). This process is repeated if
necessary until the resulting dispense rate is within the desired
range. The duty cycle (broadly, dispensing parameter) used to
achieve the calibrated medium dispense rate is saved 136 to the
tangible storage medium 64 for later use in the dispensing
mode.
[0032] Referring to FIG. 7C, after calibrating for the second
dispense rate, the powder calibration sequence continues with
calibration 138 for a third dispense rate. For example, the third
dispense rate can be less than the second dispense rate and will be
referred to as a slow dispense rate. The conveyor 16 is operated
140 for a preset time (e.g., 4 seconds) at a default conveyor
speed, such as a motor duty cycle of 18%. When the conveyor 16
stops, the scale 18 is permitted to stabilize, the amount of powder
dispensed is determined 142, and the dispense rate is determined
144. The dispenser controller 62 compares 146 the calculated
dispense rate with a preset desired dispense rate, such as the
range of 0.5 to 0.25 grains per second. If the calculated dispense
rate exceeds the desired dispense rate, the calibration cycle is
repeated 148 at a slower conveyor speed (e.g., 16% duty cycle). If
the calculated dispense rate is less than the desired dispense
rate, the calibration cycle is repeated 150 at a faster conveyor
speed (e.g., 20% duty cycle). This process is repeated as necessary
until the resulting dispense rate is within the desired range. The
duty cycle (broadly, dispensing parameter) used to achieve the
calibrated slow dispense rate is saved 152 to the tangible storage
medium 64 for later use in the dispensing mode.
[0033] It will be appreciated that the powder calibration sequence
described above is provided by way of example without limitation.
Other powder calibration sequences can be used without departing
from the scope of the present invention. For example other numbers
of calibration cycles (e.g., one) can be used. Moreover, the powder
calibration sequence can be skipped or omitted without departing
from the scope of the present invention.
[0034] When ready to dispense powder, the user can begin by
pressing the MODE actuator 86 to enter the manual dispensing mode.
Next, the user can press number actuators on the number pad 80 to
enter a target powder mass to be dispensed. This value received 154
by the dispenser controller 62 is saved to the tangible storage
medium 64 and is displayed at the second numerical display 68B.
When the user presses the execute actuator 96, the dispenser 10
will begin a dispense sequence. The dispenser controller 62
executes instructions stored on the storage medium 64 to choose 156
an initial dispense rate. To do this, the dispenser controller 62
determines 158 a mass difference by subtracting the current scale
mass reading from the target mass. In this example, assuming the
user zeroed the scale 18 with the empty tray 22 on the scale
platform 18B, the current scale mass reading would be 0 grains and
the mass difference would be the same as the target mass. The next
steps depend 160 on whether the powder calibration sequence was
performed. If yes, the powder dispense rates and associated
conveyor speeds may be used. If not, preset default powder dispense
rates and associated conveyor speeds are used, as discussed
later.
[0035] Still referring to FIG. 8A, the controller 62 proceeds to
determine 162 whether the mass difference falls into a preset one
of multiple mass difference ranges to determine whether to begin
the dispensing sequence with a dispensing cycle using the
calibrated fast, medium, or slow dispense rate. The controller 62
references a first schedule of mass difference ranges for choosing
the dispense rate for the first dispensing cycle. For example, if
the mass difference is greater than an amount A (e.g., 15 grains),
the fast dispense rate is chosen 164. If the mass difference is
less than or equal to amount A and greater than amount B (e.g., 6
grains), the medium dispense rate is chosen 166. If the mass
difference is less than or equal to amount B and greater than
amount C (e.g., 0.1 grains), the slow dispense rate is chosen 168.
If the mass difference is less than or equal to amount C and
greater than amount D (e.g., 0 grains), trickle dispensing is
chosen 170. It will be appreciated that the initial mass difference
will often be greater than amount A or greater than amount B, such
that the fast or medium dispense rate is chosen first.
[0036] Referring to FIG. 8C, assuming the fast, medium, or slow
dispense rate is chosen, the dispenser controller 62 proceeds to
choose 176 an amount of powder to be dispensed in the dispensing
cycle using that dispense rate. For example, the amount to be
dispensed in that dispensing cycle can be chosen by applying an
offset value stored in the storage medium 64. The offset value is
subtracted from the current mass difference. The fast, medium, and
slow dispense rates can have respective different offset values.
For example, the offset value for the fast flow rate can be 1
grain, the offset value for the medium flow rate can be 0.25
grains, and the offset value for the slow flow rate can be 0.1
grains. The offset value can provide a margin of error to assist in
avoiding over dispensing powder in a dispensing cycle. Other offset
values can be used without departing from the scope of the present
invention. Moreover, offset values need not be used, and the amount
of powder to be dispensed in a given dispensing cycle can be the
same as the current mass difference.
[0037] After choosing the amount of powder to be dispensed in the
dispensing cycle, the dispenser controller 62 determines 178 for
how long to operate the conveyor tube 16 in that dispensing cycle.
The dispenser controller 62 calculates this value by dividing the
chosen amount of powder to be dispensed in that dispensing cycle by
the calibrated value for the fast, medium, or slow dispense rate to
be used for that dispensing cycle. The resulting time value will be
referred to as a dispensing cycle run end time or a conveyor run
end time.
[0038] To dispense powder during the dispensing cycle, the
dispenser controller 62 operates 180 the motor 34 to turn the
conveyor tube 16 continuously until the conveyor run end time. The
motor 34 rotates the conveyor tube 16 at the motor duty cycle
(conveyor speed) saved to the storage medium 64 for the calibrated
fast, medium, or slow dispense rate during the powder calibration
sequence. For example, the motor 34 can be operated at 60% duty
cycle for the calibrated fast dispense rate, 35% duty cycle for the
medium dispense rate, or 18% duty cycle for the slow dispense rate.
It will be appreciated that the run end time can be monitored in
various ways. For example, the dispenser controller 62 can
implement a count up clock, a count down clock, or can set a future
time and continuously compare the future time to a real time
clock.
[0039] As powder is being dispensed, the dispenser controller 62
monitors 182 the dispense rate of the powder and can update or
reset the dispensing cycle run end time as needed. As powder is
dispensed and becomes supported by the scale platform 18B, the
scale 18 will begin providing scale sensor feedback to the
dispenser controller 62. The scale sensor feedback is delayed
because at any given time during the dispensing cycle, the amount
of powder supported by the scale 18 is less than the amount of
powder that has exited the conveyor tube, and because of latency in
the scale signal reaching the dispenser controller 62. For example,
if a low pass filter (or other device) is used for stabilizing the
scale signal, the dispenser controller 62 may receive the scale
signal about every 0.1 seconds. After about 0.4 seconds of rotating
the conveyor tube, the dispenser controller 62 can begin monitoring
the dispense rate of the powder being dispensed. Mass readings and
associated times are stored in a table in the tangible storage
medium about every 0.1 seconds of the dispensing cycle. The
dispenser controller 62 can determine real time dispense rate from
this data in a variety of ways. For example, each time the
dispenser controller 62 receives a scale signal, the dispenser
controller can apply a linear regression line to a plot of the
complete set of mass readings and associated times from the
dispensing cycle (time along X-axis, mass along Y-axis). The
dispenser controller 62 determines the slope of the linear
regression line and saves the slope to the tangible storage medium
64 as the current dispense rate of the powder. If the current
dispense rate of powder is different than the calibrated dispense
rate of powder for that dispensing cycle, the dispenser controller
62 adjusts or resets the dispensing cycle run end time (broadly,
dispensing parameter) by increasing 184 or decreasing 186 to the
value of the offset mass difference divided by the current dispense
rate. The dispenser controller 62 can continuously monitor 182 the
current dispense rate in this manner and repeatedly update or reset
184, 186 the dispensing cycle run end time. The monitoring of the
dispense rate and dynamic updating of the run end time can account
for irregularities caused by factors such as reduced powder supply
(and thus reduced downward pressure on remaining powder) in the
hopper 14, variations in moisture content of the powder in the
hopper, etc. It will be appreciated that the real time flow rate
can be determined in other ways, and the dispensing cycle run end
time can be determined in other ways, without departing from the
scope of the present invention.
[0040] It will be appreciated that instead of changing the
dispensing cycle run end time, the speed of the conveyor can be
changed (increased or decreased) based on the real time dispense
rate, to reduce variance of the real time dispense rate from the
desired dispense rate (e.g., calibrated dispense rate) for that
dispensing cycle. For example, the conveyor speed would be modified
184, 186 (FIG. 8C) during the dispensing cycle to achieve the
dispense rate used to determine the initial dispensing cycle run
end time. The conveyor speed could be continuously adjusted as
needed to change to maintain the real time dispense rate at the
desired dispense rate. Moreover, a combination of changing the
dispensing cycle run end time and changing the conveyor speed could
be used without departing from the scope of the present
invention.
[0041] Upon reaching 186 the dispensing cycle run end time, the
dispenser controller 62 will stop rotating 188 the conveyor tube
(see FIG. 8D). Because the dispense rate of the powder was
calibrated and monitored during the dispensing cycle, and because
the dispensing cycle run end time was repeatedly updated during the
dispensing cycle, the dispensing cycle run end time is a good
prediction of when to stop rotating the conveyor tube 16 such that
the chosen dispense amount is dispensed without over or under
dispensing. Inertia of the motor 34 and/or conveyor tube, or other
factors, may cause additional powder to fall from the conveyor
tube, and this powder is desirably less than the offset amount
applied to choose the dispense amount for the dispensing cycle. The
dispenser controller 62 waits (e.g., about 4 seconds) for the scale
reading to stabilize and then determines 190 and saves the final
mass reading for the first dispensing cycle.
[0042] Referring to FIG. 8A, the dispenser controller 62 then
determines 158 the current mass difference by subtracting the mass
of the powder currently supported by the scale 18 from the target
mass. The dispenser controller 62 then determines 162 whether the
current mass difference is in one of multiple ranges of mass
difference in the storage medium 64 to select a dispense rate for a
next dispensing cycle, if any. Instead of using the first schedule
of mass differences used for selecting the dispense rate for the
initial dispensing cycle, the dispenser controller 62 may reference
a second schedule of mass differences for dispensing cycles
subsequent to the initial dispensing cycle of a dispensing
sequence. For example, if the mass difference is greater than an
amount A (e.g., 1 grain), the fast dispense rate is chosen 164. If
the mass difference is less than or equal to amount A and greater
than amount B (e.g., 0.25 grains), the medium dispense rate is
chosen 166. If the mass difference is less than or equal to amount
B and greater than amount C (e.g., 0.1 grains), the slow dispense
rate is chosen 168. If the mass difference is less than or equal to
amount C and greater than amount D (e.g., 0 grains), trickle
dispensing is chosen 170. For example, if the current mass
difference falls into the range associated with the medium dispense
rate, the medium dispense rate will be chosen 166 for a next
dispensing cycle. On the other hand, if the current mass difference
falls into the range associated with the slow dispense rate, the
slow dispense rate will be chosen 168 for a next dispensing cycle.
In either case, the dispenser controller 62 would proceed to
execute a second dispensing cycle in a similar fashion as described
above with respect to the fast dispense rate but with the offset
value for the medium or slow dispense rates. An amount of powder to
be dispensed during that dispensing cycle would be chosen 176, a
run end time would be calculated 178, and powder would be
continuously dispensed 180 by rotating the conveyor tube 16 at the
motor duty cycle stored for that dispense rate. If the duration of
the dispensing cycle is longer than 0.4 seconds, while the powder
is being dispensed the dispense rate would be monitored 182 as
explained above and the run end time would be dynamically updated
184, 186, until reaching the run end time 186.
[0043] When the current mass difference is determined 162 to be
less than or equal to the amount C (e.g., 0.1 grains) and greater
than amount D (e.g., 0 grains), trickle dispensing is chosen 170 to
dispense the remaining amount of powder to reach the target powder
amount to finish the dispensing sequence. Referring to FIG. 8E, the
trickle dispensing cycle is different than the dispensing cycles
described above because the trickle dispensing cycle is
intermittent rather than continuous, and the trickle dispensing
cycle is terminated based on the scale 18 reading rather than on a
run end time. In the trickle dispensing cycle, an offset is not
used. In the trickle dispensing cycle, the dispenser controller 62
turns 192 the conveyor tube 16 for short preset trickle cycle
segments, such as 0.018 seconds each. The conveyor tube speed can
be the same as for the slow dispense rate (e.g., 18% motor duty
cycle). After each trickle cycle segment, the operation of the
conveyor tube 16 is paused 194 to permit the scale reading to
stabilize and be recorded 196. The dispenser controller 62 compares
198 the scale reading to the target mass. If the scale mass reading
is less than the target mass (or if the current mass difference is
greater than zero), the trickle dispensing cycle continues for
additional cycle segments as necessary. In each additional trickle
dispensing cycle segment, the conveyor tube 16 is rotated for
another 0.018 seconds. When the scale mass reading equals the
target mass, the trickle dispensing cycle and the overall
dispensing sequence is complete 200. If the scale reading happens
to be greater than the target mass, the display signals 202 an over
dispense.
[0044] When the dispensing cycle is complete, the user will
typically remove the tray 22 from the scale 18 and deposit the
powder from the tray into an ammunition shell or case (not shown).
After the tray 22 is repositioned on the scale 18, the user can
press the execute actuator 96 to manually initiate another
dispensing sequence. The dispenser 10 would execute the dispensing
sequence steps outlined above to dispense the same target mass
unless a different target mass is entered by the user. The number
of dispensing cycles and/or the mass readings at the end of each
dispensing cycle may not be the same from one dispensing sequence
to the next, but desirably the target mass is achieved at the end
of each dispensing sequence. If desired, the user can press the
MODE actuator 86 to enter an automatic dispensing mode in which the
dispenser 10 executes dispensing sequences as described above, but
the dispensing controller 62 starts the automatic dispensing
sequences in response to sensing the tray 22 repositioned on the
scale platform 18B, rather than when the user presses the execute
actuator.
[0045] After any dispensing cycle, if the scale reading is greater
than the target mass value, the dispensing sequence is terminated
174, 202 and the display 68 alerts the user that an over dispense
has occurred. If an over dispense occurs, the dispenser controller
62 reduces 204 (FIG. 8A) the stored conveyor speed (broadly,
dispensing parameter) associated with the calibrated dispense rate
that resulted in the over dispense. For example, the dispenser
controller 62 can store a lower motor duty cycle in the storage
medium 64 for that calibrated dispense rate. Desirably, the reduced
conveyor speed will not result in an over dispense in the next
dispense sequence.
[0046] As mentioned above, the powder calibration sequence can be
skipped or omitted if desired. In such a case, as shown by
comparison of FIGS. 8A and 8B, the dispensing mode would operate in
a fashion similar to described above but having some differences.
After the target mass input is received 154, and the mass
difference is calculated 158, whether the fast, medium, slow, or
trickle dispensing is used as the first dispense rate can be chosen
206, 208, 210, 212, 214 based on the same criteria discussed above
(the same values for amounts A, B, C, and D). The offsets used 176
in dispensing cycles for the fast dispense rate, medium dispense
rate, and slow dispense rate can also be the same as explained
above. However, because the actual dispense rates for the fast,
medium, and slow dispense rates were not calibrated, conservative
default preset dispense rate values are used 178. For example, the
default preset fast dispense rate may be 6 grains per second at 60%
motor duty cycle, the default preset medium dispense rate may be 3
grains per second at 35% motor duty cycle, and the default preset
slow dispense rate may be 0.5 grains per second at 18% motor duty
cycle.
[0047] To assist in preventing over dispensing, these default
preset dispense rates for the associated motor duty cycles are
intentional over estimates to account for the worst case scenario
of a rather freely flowing powder. The result is when the run end
time is calculated 178 by dividing the amount of powder to be
dispensed in a dispensing cycle by the default preset dispense
rate, the initial duration of the dispensing cycle will likely be
shorter than necessary to actually dispense the chosen amount of
powder for that dispensing cycle. However, as explained above with
reference to FIG. 8C, if the dispensing cycle lasts longer than 0.4
seconds, the real time flow rate will be monitored 182, and the run
end time will be continually updated 184, 186 based on the
calculated flow rate. In many cases, the dynamic updating or
resetting of the run end time will result in lengthening of the
dispensing cycle so that the conveyor tube 16 turns for a longer
time than initially calculated. Because the dispense rate of the
powder is monitored during the dispensing cycle, and because the
dispensing cycle run end time is repeatedly updated during the
dispensing cycle, the dispensing cycle run end time is a good
prediction of when to stop rotating the conveyor tube 16 such that
the chosen dispense amount is dispensed without over or under
dispensing. After one or more dispensing cycles, the mass
difference will desirably equal zero, and the display will signal
216 to the user that dispensing is complete, but if too much powder
was dispensed, the display will signal 218 an over dispense.
Assuming the same powder and the same ending target powder mass, a
dispensing sequence without prior powder calibration may take
longer than a dispensing sequence with prior powder calibration,
but will desirably be about as precise in dispensing the chosen
amount of powder for each dispensing cycle and in meeting the exact
target mass at the end of the dispensing sequence.
[0048] When a prior powder calibration sequence was not used, a
first powder dispensing sequence can be viewed in a sense as a
calibration sequence. More specifically, when a dispensing cycle is
performed, the actual dispense rate of the powder is determined 182
and can be saved to the storage medium 64 as associated with the
default preset motor duty cycle. The next time a dispensing cycle
calls for use of that motor duty cycle, the dispenser controller 62
can use the saved actual dispense rate for the powder to calculate
a more accurate initial run end time (broadly, dispensing
parameter).
[0049] As with a dispensing sequence with prior powder calibration
that results in an over dispense, a dispensing sequence without
prior powder calibration that results 218 in an over dispense can
cause the dispenser controller 62 to reduce 220 the stored speed of
the conveyor tube 16 (e.g., the stored motor duty cycle, a
dispensing parameter) to dispense the powder at a lesser rate next
time that category of dispense rate (fast, medium, or slow) is
used, to assist in preventing another over dispense.
Example 1
[0050] Assume a user would like to perform a powder calibration
pursuant to FIGS. 7A-7C and then dispense a load of 50 grains of
powder pursuant to FIGS. 8A and 8C-8E. The user supplies the powder
to the hopper 14. The user presses the POWDER CAL actuator 84. The
conveyor tube 16 rotates for 4 seconds to prime the conveyor tube.
They conveyor tube 16 stops rotating and the signal from the scale
sensor 40 is permitted to stabilize. The dispenser controller 62
uses the mass reading as its 0 point. Then the conveyor tube 16
turns at the preset default 60% motor duty cycle for 4 seconds. The
conveyor tube 16 stops rotating and the signal from the scale
sensor 40 is permitted to stabilize. The dispenser controller 62
subtracts the scale mass reading from the mass reading after
priming to yield 25 grains. The 25 grains is divided by the 4
seconds to calculate 6.25 grains per second dispense rate. Because
the 6.25 grains per second is outside the range of 4 to 6 grains
per second, the calibration cycle for the fast flow rate is
repeated with a lower duty cycle of 55% (broadly, dispensing
parameter). After turning the conveyor tube 16 at the 55% motor
duty cycle for 4 seconds, the dispenser controller 62 determines 20
grains were dispensed based on the scale mass reading. The 20
grains is divided by the 4 seconds to yield 5 grains per second
dispense rate. Because the 5 grains per second is within the range
of 4 to 6 grains per second, 5 grains per second is stored as the
fast dispense rate along with its associated motor duty cycle of
55% for use later in a dispensing cycle. The dispenser controller
62 then proceeds to perform a calibration cycle for the medium
dispense rate. The conveyor tube 16 is turned at the default preset
35% motor duty cycle for 4 seconds. The dispenser controller 62
determines 10 grains was dispensed and divides the 10 grains by the
4 seconds to yield 2.5 grains per second dispense rate. Because the
2.5 grains per second is in the range of 1.5 to 3 grains per
second, the 2.5 grains per second is stored as the medium dispense
rate along with the associated 35% motor duty cycle (broadly,
dispensing parameter) for later use in a dispensing cycle. The
dispenser controller 62 then proceeds to perform a calibration
cycle for the slow dispense rate. The conveyor tube 16 is turned at
the default preset 18% motor duty cycle for 4 seconds. The
dispenser controller 62 divides a resulting 1.6 grains by the 4
seconds to yield 0.4 grains per second dispense rate. Because the
0.4 grains per second is in the range of 0.25 to 0.5 grains per
second, the 0.4 grains per second is stored as the slow dispense
rate along with the associated 18% motor duty cycle (broadly,
dispensing parameter). The calibration sequence is complete.
[0051] To proceed with dispensing the desired 50 grain load of
powder, the user empties the powder from the tray 22 from the
calibration sequence. After replacing the tray 22 on the scale 18,
and entering 50 grains target mass via the user input 66, the user
presses the execute actuator 96. The dispenser controller 62
proceeds to execute a dispensing sequence. Because the initial mass
difference of 50 grains is greater than the 15 grain threshold, the
dispenser controller 62 decides to use the fast dispense rate for
the first dispensing cycle. The dispenser controller 62 calculates
the amount of powder to be dispensed in the first dispensing cycle
by subtracting the offset value of 1 grain from the 50 grain mass
difference. The dispenser controller 62 then calculates the amount
of time to turn the conveyor tube 16 (run end time) by dividing the
49 grains by the calibrated fast dispense rate of 5 grains per
second, yielding a run end time of 9.8 seconds (broadly, dispensing
parameter). The conveyor tube motor 34 is energized and turns at
the 55% motor duty cycle determined during powder calibration.
Because the duration of the dispensing cycle is greater than 0.4
seconds, the dispenser controller 62 monitors the real time
dispense rate and updates the run end time as necessary. In this
case, the run end time is reset several times while dispensing
powder, and the conveyor tube 16 stops rotating at 9.9 seconds
instead of 9.8 seconds. The calculated real time dispense rate of
4.95 grains per second used to calculate the 9.9 seconds run end
time is saved to the tangible storage medium 64 as the fast
dispense rate for the next dispensing cycle calling for the fast
dispense rate. When the motor 34 is deenergized, 49 grains had
exited the conveyor tube, but an additional 0.1 grains exited the
tube before the tube ultimately stopped moving. The dispenser
controller 62 waits 0.4 seconds for the scale 18 to stabilize. The
current mass difference is determined to be 0.9 grains (50 grains
target mass minus dispensed 49.1 grains). Because the 0.9 grains is
in the range of 1.0 to 0.25 grains, the dispenser controller 62
chooses the medium dispense rate for the next dispensing cycle. The
amount of powder to be dispensed in the second dispensing cycle is
calculated by subtracting the offset of 0.25 grains from the 0.9
grains mass difference, yielding 0.65 grains. The 0.65 grains is
divided by the calibrated medium dispense rate of 2.5 grains per
second to give a 0.26 second run end time (dispensing parameter).
The dispenser controller 62 then turns the conveyor tube 16 at the
35% motor duty cycle (dispensing parameter) until the run end time.
The resulting mass of powder supported by the scale 18 is 49.8
grains. Because the mass difference is now 0.2 grains, in the range
of 0.25 to 0.1 grains, the dispenser controller 62 chooses the slow
dispense rate for the next dispensing cycle. The amount of powder
to be dispensed is calculated by subtracting the offset of 0.1
grains from the 0.2 grains mass difference, yielding 0.1 grains.
The 0.1 grains is divided by the calibrated slow dispense rate of
0.4 grains per second to give a 0.25 second run end time. The
dispenser controller 62 then turns the conveyor tube 16 at the 18%
motor duty cycle until the run end time. The resulting mass of
powder supported by the scale 18 is 49.9 grains. Because the mass
difference is now 0.1 grains, the dispenser controller 62 chooses
trickle dispensing for the next dispensing cycle. The dispenser
controller 62 turns the conveyor tube 16 for 0.018 seconds at the
18% motor duty cycle and then waits 0.4 seconds for the scale 18 to
stabilize. The scale mass reading is still not equal to the target
mass of 50 grains, so the dispenser controller 62 turns the
conveyor tube 16 for another 0.018 seconds at the 18% motor duty
cycle. Now, the mass difference is 0 because the scale mass reading
is 50 grains, the same as the target mass. The dispensing sequence
is complete. The user empties the powder from the tray 22 to the
ammunition shell or case and replaces the tray on the scale 18.
Example 2
[0052] Assume a user would like to dispense a load of 14 grains of
powder pursuant to FIGS. 8A-8E without first performing a powder
calibration. The user supplies the powder to the hopper 14 and
primes the conveyor tube. To proceed with dispensing the load of
powder, the user enters 14 grains target mass via the user input
66, and then presses the execute actuator 96. The dispenser
controller 62 proceeds to execute a dispensing sequence. Because
the initial mass difference of 14 grains is less than 15 grains and
greater than 6 grains, the dispenser controller 62 decides to use
the medium dispense rate for the first dispensing cycle. The
dispenser controller 62 calculates the amount of powder to be
dispensed in the first dispensing cycle by subtracting the offset
value of 0.25 grains to yield 13.75 grains. The run end time
(dispensing parameter) is calculated as 4.6 seconds by dividing the
13.75 grains by the 3 grains per second preset default medium
dispense rate. The conveyor tube motor 34 is energized and turns at
the default preset 35% motor duty cycle until the run end time.
Because the duration of the dispensing cycle is greater than 0.4
seconds, the dispenser controller 62 monitors the real time
dispense rate and updates the run end time as necessary. In this
case, the run end time is reset several times, and the conveyor
tube 16 stops rotating at 4.9 seconds instead of 4.6 seconds. The
calculated real time dispense rate of 2.8 grains per second used to
calculate the 4.9 seconds run end time is saved to the tangible
storage medium 64 as the medium dispense rate for the next
dispensing cycle calling for the medium dispense rate. When the
motor 34 is deenergized, 13.75 grains had exited the conveyor tube,
but an additional 0.05 grains exited the tube before the tube
ultimately stopped moving. The dispenser controller 62 waits 0.4
seconds for the scale 18 to stabilize. The current mass difference
is determined to be 0.2 grains (14 grains target mass minus
dispensed 13.8 grains). Because the 0.2 grains is in the range of
0.25 to 0.1 grains, the dispenser controller 62 chooses the slow
dispense rate for the next dispensing cycle. The amount of powder
to be dispensed in the second dispensing cycle is calculated by
subtracting the offset of 0.1 grains from the 0.2 grains mass
difference, yielding 0.1 grains. The 0.1 grains is divided by the
preset default slow dispense rate of 0.5 grains per second to give
a 0.2 second run end time (dispensing parameter). The dispenser
controller 62 then turns the conveyor tube 16 at the preset default
18% motor duty cycle (dispensing parameter) until the run end time.
Because the dispensing cycle is less than 0.4 seconds long, the
dispenser controller 62 does not have enough time to reliably
monitor the real time dispense rate, and the run end time is not
dynamically updated. The resulting mass of powder supported by the
scale 18 is 13.9 grains. Because the mass difference is now 0.1
grains, trickle dispensing is chosen for the next dispensing cycle.
The dispenser controller 62 turns the conveyor tube 16 for 0.018
seconds at the 18% motor duty cycle and then waits 0.4 seconds for
the scale 18 to stabilize. The scale mass reading is still not
equal to the target mass of 14 grains, so the dispenser controller
62 turns the conveyor tube 16 for another 0.018 seconds at the 15%
motor duty cycle. Now, the mass difference is 0 because the scale
mass reading is 14 grains, the same as the target mass. The
dispensing cycle is complete. The user empties the powder from the
tray 22 to the ammunition shell or case and replaces the tray on
the scale 18.
[0053] It will be understood that in use the dispenser 10 can
operate in other ways than described in the examples above. For
example, in some instances, no second dispensing cycle will be
required because the mass difference is zero after the first
dispensing cycle.
[0054] In a contemplated variation, the dispenser 10 can include an
encoder arranged to read rotational position of the dispenser tube
16 such that rotation of the tube can be used as a frame of
reference in carrying out steps such as explained above. In this
variation, "dispense rate" can be determined as mass per unit of
rotation (e.g., full 360 degree rotation) of the dispenser tube 16.
Moreover, the "run end time" can be referenced as a total number of
units of rotation of the conveyor tube 16. For example, instead of
the controller 62 learning and using dispense rates in terms of
grains per second, the controller can do so in terms of grains per
unit of rotation of the conveyor tube. When the controller knows
how many grains of powder are dispensed per unit of rotation, the
controller can determine and implement the "run end time" in terms
of a total number of units of rotation of the conveyor tube. Thus,
as used herein, the term "dispense rate" can also mean mass per
rotation of the conveyor tube, and the term "run end time" can also
mean number of rotations at which the conveyor tube stops rotating.
The algorithm and steps explained above, can be executed in terms
of grains per rotation rather than grains per second without
departing from the scope of the present invention. The dispenser
controller 62 could count the number of rotations of the conveyor
tube 16 and stop rotating the conveyor tube at the run end time,
i.e., when the total number of units of conveyor tube rotation is
reached. While dispensing, the controller 62 could monitor the
grains per rotation dispense rate in real time, and adjust the run
end time (total number of units of rotation) accordingly.
[0055] It will be appreciated that the speed at which the
controller 62 operates the conveyor tube 16 during a dispensing
cycle can be variable or constant without departing from the scope
of the present invention.
[0056] It will be appreciated that amounts of powder can be
referenced by mass or by weight without departing from the scope of
the present invention. The weight of an object is a product of that
object's mass because weight is mass multiplied by the force of
gravity. Thus, weight is considered to be an equivalent of mass for
purposes of the claimed inventions. Moreover, as used herein, the
term mass is defined to mean true mass (not accounting for the
force of gravity) or weight, which accounts for the force of
gravity.
[0057] In view of the above, it will be appreciated that the
tangible storage medium 64 stores instructions executable by the
dispenser controller to perform the actions described above.
[0058] For purposes of illustration, programs and other executable
program components, such as the operating system, are illustrated
herein as discrete blocks. It is recognized, however, that such
programs and components reside at various times in different
storage components of a computing device, and are executed by one
or more data processors of the device.
[0059] Embodiments of the aspects of the invention may be described
in the general context of data and/or processor-executable
instructions, such as program modules, stored one or more tangible,
non-transitory storage media and executed by one or more processors
or other devices. Generally, program modules include, but are not
limited to, routines, programs, objects, components, and data
structures that perform particular tasks or implement particular
abstract data types. Aspects of the invention may also be practiced
in distributed computing environments where tasks are performed by
remote processing devices that are linked through a communications
network. In a distributed computing environment, program modules
may be located in both local and remote storage media including
memory storage devices.
[0060] In operation, processors, computers and/or servers may
execute the processor-executable instructions (e.g., software,
firmware, and/or hardware) such as those illustrated herein to
implement aspects of the invention.
[0061] Embodiments of the aspects of the invention may be
implemented with processor-executable instructions. The
processor-executable instructions may be organized into one or more
processor-executable components or modules on a tangible processor
readable storage medium. Aspects of the invention may be
implemented with any number and organization of such components or
modules. For example, aspects of the invention are not limited to
the specific processor-executable instructions or the specific
components or modules illustrated in the figures and described
herein. Other embodiments of the aspects of the invention may
include different processor-executable instructions or components
having more or less functionality than illustrated and described
herein.
[0062] The order of execution or performance of the operations in
embodiments of the aspects of the invention illustrated and
described herein is not essential, unless otherwise specified. That
is, the operations may be performed in any order, unless otherwise
specified, and embodiments of the aspects of the invention may
include additional or fewer operations than those disclosed herein.
For example, it is contemplated that executing or performing a
particular operation before, contemporaneously with, or after
another operation is within the scope of aspects of the
invention.
[0063] When introducing elements of aspects of the invention or the
embodiments thereof, the articles "a," "an," "the," and "said" are
intended to mean that there are one or more of the elements. The
terms "comprising," "including," and "having" are intended to be
inclusive and mean that there may be additional elements other than
the listed elements.
[0064] In view of the above, it will be seen that several
advantages of the aspects of the invention are achieved and other
advantageous results attained.
[0065] Not all of the depicted components illustrated or described
may be required. In addition, some implementations and embodiments
may include additional components. Variations in the arrangement
and type of the components may be made without departing from the
spirit or scope of the claims as set forth herein. Additional,
different or fewer components may be provided and components may be
combined. Alternatively or in addition, a component may be
implemented by several components.
[0066] The above description illustrates the aspects of the
invention by way of example and not by way of limitation. This
description enables one skilled in the art to make and use the
aspects of the invention, and describes several embodiments,
adaptations, variations, alternatives and uses of the aspects of
the invention, including what is presently believed to be the best
mode of carrying out the aspects of the invention. Additionally, it
is to be understood that the aspects of the invention is not
limited in its application to the details of construction and the
arrangement of components set forth in the description or
illustrated in the drawings. The aspects of the invention are
capable of other embodiments and of being practiced or carried out
in various ways. Also, it will be understood that the phraseology
and terminology used herein is for the purpose of description and
should not be regarded as limiting.
[0067] It will be apparent that modifications and variations are
possible without departing from the scope of aspects of the
invention as defined in the appended claims. It is contemplated
that various changes could be made in the above constructions,
products, and methods without departing from the scope of aspects
of the invention. In the preceding specification, various
embodiments have been described with reference to the accompanying
drawings. It will, however, be evident that various modifications
and changes may be made thereto, and additional embodiments may be
implemented, without departing from the broader scope of the
aspects of the invention as set forth in the claims that follow.
The specification and drawings are accordingly to be regarded in an
illustrative rather than restrictive sense.
* * * * *