Abstrict A method and apparatus for efficient dispensing of desiccant canisters
into containers is disclosed. The apparatus includes a microprocessor
that monitors a plurality of sensors, and applies control signals
to a servomotor that controls a rotary disc that transports desiccant
canisters from a drop chute to containers. The containers pass through
the apparatus via a conveyor system. Control signals determine the
position and presence of desiccant canisters and containers to ensure
proper operation. Error detection and recovery features are provided
to handle the case of a missing desiccant canister, and halt the
apparatus upon detection of an unrecoverable error.
Claims 1. A method of dispensing a desiccant canister into a container,
comprising the steps of: a. positioning a disc such that a vacant
area within said disc is located at a transfer station; b. inserting
a desiccant canister into said vacant area of said disc at said
transfer station; c. verifying the presence of said desiccant canister
in said vacant area of said disc; d. activating a conveyor signal
to move a container into a dispensing station; e. verifying presence
of said container at said dispensing station; f. rotating said disc,
whereby said desiccant canister is located at said dispensing station
directly above said container; and g. stopping said disc, whereby
said desiccant canister drops into said container.
2. The method of claim 1 whereby the step of positioning said
disc such that a vacant area with in said disc is located at a transfer
station comprises the steps of: a. rotating said disc a predetermined
number of degrees; b. detecting the position of a dowel mounted
on said disc, said dowel being located on a radial line traveling
through the centerline of said vacant area; c. receiving input from
a dowel sensor; and d. stopping rotation of said disc when input
from said dowel sensor indicates that said dowel has arrived at
a predetermined position.
3. An apparatus for dispensing a desiccant canister into a container,
comprising: a. a drop chute for inputting a desiccant canister into
the apparatus; b. a disc with a plurality of vacant areas for transporting
said desiccant canister to a sensing station; c. sensing means at
said sensing station for indicating the presence of said desiccant
canister within a vacant area of said disc; d. a motor for moving
said disc to transport said desiccant canister; e. sensing means
at a dispensing station to verify presence of a container at a dispensing
station; and f. sensing means at a dispensing station to verify
the dispensing of said desiccant canister into said container at
said dispensing station.
4. The apparatus of claim 3 wherein said disc further comprises
a dowel, located on a radial line, between the center of said disc,
and center of each said vacant area.
5. The apparatus of claim 3 wherein said motor is a servomotor
with an integrated servomotor controller.
6. The apparatus of claim 5 further comprising a planetary gearbox,
whereby said servomotor rotates said disc via said planetary gearbox.
7. The apparatus of claim 4 wherein said sensing means at said
sensing station for indicating the presence of said desiccant canister
within a vacant area of said disc comprises an inductive proximity
sensor, whereby said inductive proximity sensor generates a signal
when said dowel is substantially close to said inductive proximity
sensor.
8. The apparatus of claim 3 wherein said sensing means at a dispensing
station to verify the dispensing of said desiccant canister into
said container at said dispensing station comprises a laser beam
emitter and a laser beam receiver, said laser beam emitter oriented
opposite to said laser beam receiver, whereby a falling desiccant
canister causes an interruption in a laser beam between said laser
beam emitter and said laser beam receiver, said interruption providing
an indication of a successfully dispensed desiccant canister.
9. A method for verifying successful dispensing of a desiccant
canister into a container, comprising the steps of: a. sensing a
desiccant canister at a sensing station; b. sensing a container
at a discharge station; c. sensing a desiccant canister dropping
into said container at said discharge station; whereby an error
signal is generated if at least one of said steps fails.
10. The method of claim 9 further comprising the steps of: a.
indexing to the next desiccant canister when said sensing a desiccant
canister at said sensing station fails; b. sensing said next desiccant
canister at said sensing station; c. halting the transport of desiccant
canisters when a predetermined number of missing desiccant canister
events have been detected.
Description FIELD OF THE INVENTION
[0001] The present invention relates packaging equipment systems.
More specifically the present invention relates to a method and
apparatus for automating the delivery of desiccant canisters into
a container.
BACKGROUND
[0002] Desiccants are often included in a packaged product to reduce
moisture within the packaging. In particular, for pharmaceutical,
food, chemical, and personal healthcare products, there is often
a need for a desiccant to be placed in the container along with
the product. To facilitate mass production, it is desirable to provide
an efficient means for dispensing desiccant canisters into the product
containers.
SUMMARY OF THE INVENTION
[0003] The present invention provides an improved method and apparatus
for automating the delivery of desiccant canisters into a container.
The apparatus of the present invention has a microprocessor that
receives input signals from various sensors that provide information
about the presence and position of desiccant canisters and containers.
The microprocessor utilizes the information provided by these sensors
to determine the appropriate control parameters for the motor and
air flow that serve to move the desiccant through a predetermined
path to the container.
[0004] It is an aspect of the present invention to provide a desiccant
dispensing apparatus that can accommodate various different sized
containers at a reduced cost. The apparatus of the present invention
accomplishes this by eliminating the star-wheel commonly found on
desiccant dispensing machines. Typically a separate star-wheel and
corresponding dispenser disc would be required for each configuration.
By eliminating the star-wheel, the cost for accommodating multiple
configurations is dramatically reduced.
[0005] It is another aspect of the present invention to provide
a desiccant dispensing apparatus with reduced changeover time. The
present invention utilizes a dispenser disc that accommodates all
container sizes. There is no star-wheel to change out, hence changeover
time is reduced.
[0006] It is another aspect of the present invention to provide
a desiccant dispensing apparatus that provides a more precise placement
of desiccant within the container. This is accomplished in the present
invention by bring the dispensing disc to a complete stop before
dispensing the desiccant canister. Other dispensing apparatuses
dispense desiccant while the dispensing disc is rotating. This causes
the desiccant to be dispensed with an angular motion due to momentum
and centrifugal force. With the apparatus of the present invention,
the desiccant is dispensed into the container in vertical attitude.
[0007] It is another aspect of the present invention to provide
increased throughput. The apparatus of the present invention includes
a microprocessor based control system that allows desiccant to be
dispensed at a higher rate than continuously rotating dispensing
devices, which operate in the general range of 1 to 50 rpm typically.
The dispensing apparatus of the present invention has an operating
range of approximately 2000 rpm, which is considerably faster.
[0008] The desiccant dispensing apparatus of the present invention
will be referred to as a Canister Desiccant Feeder Rotary (CDFR)
for the purposes of this disclosure.
[0009] The aforementioned aspects, and other advantages of the
CDFR will be explained in detail in the following sections.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a side view of a rotary desiccant feeder method
and apparatus of the present invention.
[0011] FIG. 2 is a transverse sectional view showing internal parts
for the rotary desiccant feeder.
[0012] FIG. 3 is a front view of the rotary desiccant feeder.
[0013] FIG. 4 is a perspective view of the rotary desiccant feeder.
[0014] FIG. 5 is a top plan view of the rotary desiccant feeder.
[0015] FIG. 6 is an exploded perspective view of the rotary desiccant
feeder.
[0016] FIG. 7 is a side view of the desiccant dispensing apparatus
and system showing containers passing through the desiccant loading
station.
[0017] FIG. 8 is a transverse sectional view showing desiccant
discharging into containers.
[0018] FIG. 9 is an end view showing containers aligned with the
desiccant discharge station.
[0019] FIG. 10 is a top plan view showing empty containers before
the discharge station and filled containers downstream of the desiccant
feeder apparatus and system.
[0020] FIG. 11 is a transverse sectional view showing various stations
including a transfer station (St), the desiccant sensing station
(Ss), the discharge station (Sd) and the empty discharge station
(Se).
[0021] FIG. 12 is a perspective cutaway view showing various stations
including a transfer station (St), the desiccant sensing station
(Ss), and the discharge station (Sd).
[0022] FIG. 13 is a system block diagram of the dispensing apparatus
of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0023] Referring to FIG. 13 microprocessor 105 is configured to
receive input from a plurality of sensors 110 provide information
about the presence and position of desiccant canisters and containers.
The sensors include a container present sensor 125 desiccant present
sensor 130 desiccant drop sensor 5 and a dispenser disc home sensor
15. Microprocessor 105 is also in communication with a servomotor
4. The servomotor 4 includes an integrated servomotor controller
4a, which controls the servomotor that moves the transport mechanism
that moves the desiccant canisters. Microprocessor 105 is also connected
to a user interface 120 that allows the user to configure the apparatus
for a particular job, and provides feedback, such as operating parameters
and statistics, to the user.
[0024] The reader should now refer to FIGS. 1 through 12 for the
following description. Canister desiccants are fed to the CDFR from
a bowl sorting device that arranges the desiccant into a single
column of desiccant canisters in a base up and base down attitude.
The desiccant canisters are transferred to the CDFR via drop chute
18. Drop chute 18 is connected to CDFR dispenser housing 1 via chute
adapter flange 16. A rotary disc 12 in the CDFR has a plurality
of vacant areas with rotary disc 12 referred to as pocket holes,
generally referenced as 12a. These pocket holes 12a are used to
transport desiccant canisters from the chute adapter flange 16
to a container 30. As the rotary disc 12 rotates, pocket holes 12a
are passed through three key positions (See FIG. 11): Transfer station
(St) is the position where the desiccant canister is transferred
from the drop chute 18 to the rotary disc 12. Sensing station (Ss)
is where the presence of a desiccant canister is verified. Discharge
station (Sd) is where the desiccant canister is released into a
waiting container 30 (See FIG. 9). While the embodiment shown uses
a separate transfer station (St) and sensing station (Ss), it is
possible to combine the transfer station (St) and sensing station
(Ss) into a single position. The flow of the desiccant canister
through these key positions will now be described.
[0025] The desiccant canister 29 upon traveling through drop chute
18 lands at transfer station (St) in a pocket hole of rotary disc
12 (see FIG. 11). The CDFR has an integrated servomotor 4 and servomotor
controller 4a. For the purposes of this disclosure, the integrated
servomotor and servomotor controller will be referred to simply
as "servomotor". Servomotor 4 is attached to CDFR dispenser
housing 1 and rotates the disc mounting hub 10 via planetary gearbox
3 to provide the rotary motion to the CDFR dispenser disc 12 (See
FIG. 6). A CDFR dispenser housing nose 9 is removable to provide
access to the CDFR for maintenance and servicing. Power and input/output
(IO) lines are connected to servomotor 4 via a plurality of cables,
indicated as items 24 and 25 in FIG. 6. The 10 signals are connected
to microprocessor 105 via a wiring harness (not shown) to allow
microprocessor 105 to monitor input from the sensors, and issue
the appropriate commands to servomotor 4.
[0026] Servomotor 4 indexes rotary disc 12 to sensing station (Ss).
At sensing station.(Ss), desiccant present sensor 130 receives input
from diffuse fiber optic cable 13 to verify the presence of a desiccant
canister 29 in pocket hole 12a of rotary disc 12. A container present
sensor 125 comprised of laser beam receiver 7 and laser beam emitter
8 (See FIG. 9) detect the presence of a container underneath discharge
station (Sd). If a container is detected at discharge station (Sd),
then rotary disc rotates to transport the desiccant canister 29
from sensing station (Ss) to discharge station (Sd) whereby the
desiccant canister 29 drops by gravity into the container 30 at
the discharge station (Sd). A desiccant drop sensor 5 preferably
an optical sensor, verifies that the desiccant canister 29 successfully
dispensed into container 30. The pocket hole 12a is now empty, and
is able to receive another desiccant canister to be dispensed.
[0027] Typical configurations of rotary disc 12 would provide a
pocket hole 12a arrangement conducive to the desiccant size in grams,
based on the height and diameter of desiccant canister 29 and the
maximum number of desiccant canisters to be dispensed into the container
30.
[0028] The number of desiccant pockets holes 12a in an arrangement
is divided into 360 degrees of rotary disc 12 at equal angles around
the center point, i.e. Example configurations include 6 pocket holes
at 60 degree increments, and 4 holes at 90 degree increments. Other
configurations are possible without departing from the scope of
the present invention.
[0029] The pocket holes 12a are arranged on rotary disc 12 at predetermined
radius Rh. For each pocket hole 12a, a corresponding dowel pin 26
is pressed in to rotary disc 12 along the centerline between center
of pocket hole 12a, and center of rotary disc 12 at radius Rd (See
FIG. 12). Dowel pins 26 are utilized provide feedback of the pocket
hole 12a location to the servomotor 4.
[0030] The servomotor 4 via its integrated motor controller, provides
an encoder pulse count for positioning the desiccant pocket holes
12a within the rotary disc 12 to align with the CDFR dispenser housing
cover 2 and the discharge hole 2a in the CDFR dispenser housing
cover 2 (See FIG. 2). An incremental motion profile equal to the
angle of the desiccant pocket holes 12a in the rotary disc 12 and
the encoder pulse count ensure the motion for incremental move of
the rotary disc 12 aligns to the discharge hole 2a in the CDFR dispenser
housing cover 2. The servomotor 4 allows for the user to contour
the profile of the rotary disc 12 motion for a given desiccant size
and weight, container size and output rate. Program parameters of
the servomotor 4 include the acceleration, deceleration and velocity
of the rotary disc 12 to achieve a given output rate.
[0031] To index a pocket hole 12a to the next position, the servomotor
4 rotates rotary disc 12 until the next dowel pin 26 arrives at
disc home sensor 15 (See FIGS. 4 and 6). In a preferred embodiment,
disc home sensor 15 is an inductive proximity sensor that serves
as a dowel sensor. Thus, by locating the position of the dowel 26
the corresponding pocket hole 12a is in a known position. Servomotor
4 rotates a predetermined number of degrees, based on the configuration
of rotary disc 12. For example, if rotary disc 12 has 6 pocket holes
12a, then servomotor 4 will rotate 60 degrees. The fine positioning
of the rotary disc will then be performed, based on feedback from
disc home sensor 15.
[0032] The CDFR provides error monitoring and recovery functions
during its operation. During normal operation, containers are delivered
to the desiccant feeder of the present invention by conventional
conveyor systems and are aligned so that the open end of the containers
is properly aligned and passes under the discharge station (Sd).
Specifically, FIG. 8 shows a plurality of containers, indicated
as reference 30 on a conveyor (not shown) that are to receive a
desiccant canister from the CDFR. Container 30a is at discharge
station (Sd). Desiccant canister 29a is about to be dispensed into
container 30a. Containers indicated as 30b already have received
a desiccant canister 29b.
[0033] If no desiccant canister 29 is sensed at the sensing station
(Ss), an error signal E1 is generated (See FIG. 13). This signal
can serve to stop or slow the conveyor. As an initial error recovery
strategy, rotary disc 12 is rotated to place the next pocket hole
12a at the sensing station (Ss). If a desiccant canister 29 is now
present, error signal E1 is cleared, and normal operation resumes.
This allows operation to continue uninterrupted, even if a desiccant
canister occasionally fails to arrive at transfer station (St) during
a particular cycle. After a predetermined number of attempts, the
CDFR is halted, as a more serious error is likely. Similarly, at
discharge station (Sd), if desiccant drop sensor 5 does not detect
a desiccant canister dispensing into container 30 error signal
E1 is generated, and the CDFR is halted.
[0034] If a jam at the discharge station (Sd) prevents dispensing
of desiccant canister 29 the rotary disc 12 rotates desiccant canister
29 beyond the discharge station (Sd) to the exit station (Se), whereby
the desiccant canister can then exit the CDFR.
[0035] Accordingly, the reader will see that the present invention
provides an efficient means for dispensing desiccant canisters into
containers. Although the descriptions above contain many specific
details, these should not be construed as limiting the scope of
the invention, but merely as providing illustrations of some of
the presently preferred embodiments of this invention. Thus, the
scope of the invention should be determined by the appended claims
and their legal equivalents, rather than by the examples given. |