Note: Descriptions are shown in the official language in which they were submitted.
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PILL CRUSHER
FIELD OF THE INVENTION
The present invention relates to pill crushers and, more particularly, to
electrically
operated pill crushers.
BACK GROUND OF THE INVENTION
Some patients for whom medication is provided in the form of pills, because of
their
poor medical conditions, have difficulty in swallowing the pills. It has
therefore previously been
proposed to provide a pill crusher, by means of which pills can be crushed
into a powder form. The
powder produced in this way can then be added to a liquid to provide a mixture
which is more
easily consumable by such patients.
In most healthcare facilities, crushing pills for patients is a frequently
performed
task. At the present time, pills are usually crushed by employing a manual
pill crusher, but this
frequently results in the manual exertion of high forces, or postures and
repetitive movements that
can contribute to injuries of the hands, wrists and shoulders. Furthermore,
inhalation of airborne
dust, which occurs during the crushing process, has also been reported to be a
problem.
To reduce the magnitude of the forces required to crush pills, manufacturers
of
manual pill crushers have designed lever-type mechanical devices employing a
metal head attached
to a lever arm which pivots about a fulcrum.
However, even with the use of such lever-type mechanical devices, the forces
required are often still high, and the users are still required to assume
awkward postures and to
perform repetitive movements. Awkward postures of the shoulder occur because
pill crushers are
typically placed on the tops of medication carts and the heights of the top
surfaces of the medication
carts are usually too high for most workers. The design of a typical lever-
type crusher is such that
downward forces are required to be exerted on a straight handle, which results
in awkward postures
of the wrist.
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Examples of prior manually actuated pill crushers are disclosed, for example,
in
United States Patents Numbers 2,631,786; 3,915,393; 6,059,209 and 6,357,679.
In United States Patent Number 6,508,424 there is disclosed a battery operated
pill
crusher comprising a cylindrical plunger which can be moved downwardly into a
cylindrical
container, the bottom of which is in the form of a turntable which can be
rotated by an electric
motor and which has an upper surface formed with a plurality of grinding
protrusions. In use of this
prior device, a pill is inserted between the upper surface of the turntable
and the plunger, the
plunger is pressed downwardly and the turntable is then rotated, so that
rotational motion as well as
compression is applied to the pill, which is thereby pulverized. However, this
prior device has the
disadvantage that it is necessary to press the plunger down manually toward
the turntable, which is
resiliently mounted, so that the crushing forces which can be exerted on the
pill are limited. Another
disadvantage of this prior device is the risk that rotation of the turntable
could be initiated by
pressing directly onto the turntable with, for example, a finger, while the
plunger is removed.
Canadian Patent Number 2,057,245 discloses a pill crusher and grinder for use
especially in nursing homes and domestic environments, the pill crusher and
grinder having a pill or
tablet-receiving and holding means, a rotary crushing and grinding means
having a rotary shaft, a
tablet contacting element on one end of the shaft and rotatable therewith and
means for rotating the
shaft. In a preferred embodiment, the shaft is adapted firstly to break the
tablet into small pieces and
then to crush and grind it by rotary action within the pill receiving and
holding means. The means
for rotating the shaft is a manually operable handle. The rotary shaft is
screw-threaded and is
received in a complementary screw-threaded receiver, which is fixed with
respect to the tablet
receiving and holding means. However, this prior device has the disadvantage
that it employs rotary
blades, which can pose a safety hazard.
In United States Patent Number 5,067,666 there is disclosed a battery operated
pill
crusher comprising a selectively activatable motor to produce a power source
to a cam-driven ram
which reciprocates once on a vertical axis into and out of engagement with a
pill in a medication
cup with sufficient force to "smash" the pill. The ram is returned to its
uppermost position by the
coaction of the eccentric cam and a compression spring operatively
circumscribed thereabout.
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However, this prior device has the disadvantage that the ram does not rotate
while being displaced,
so that the crushing abilities which can be exerted on the pill are limited.
Another disadvantage of
this prior device is the use of a compression spring to retract the plunger,
which may weaken its
ability to retract the plunger over time.
SUMMARY OF THE INVENTION
According to the present invention, there is provided a pill crusher which
comprises
a paper cup receptacle having an upwardly open, frusto-conical recess for
receiving a paper cup, a
plunger having a frusto-conical shape complimentary to that of the recess, the
plunger being above
and coaxial with the recess, an electric motor and a reciprocatory drive
transmission between the
electric motor and the plunger.
In a preferred embodiment of the present invention, the reciprocatory drive
transmission comprises a worm and nut drive transmission, and a drive control
is connected to the
electric motor which comprises means for energizing the motor so as to
displace the plunger into
and out of the recess.
When the pill crusher according to the present invention is in operation, a
paper cup
is inserted into the receptacle, at least one pill is inserted into the paper
cup and preferably, a second
paper cup is inserted into the first paper cup, so that the pill or pills
is/are located between the two
paper cups in order to prevent cross-contamination. The electric motor is then
energized under the
control of the drive control so as to displace the plunger into the second
paper cup and the recess in
the receptacle until reaching a first predetermined distance or a
predetermined pressure, which is
sufficient to ensure that the pill is broken into segments or crushed. During
this stroke, the plunger
is rotated by the worm and nut drive, so that the pill is subjected to both
rotational forces and
compression forces, and the pill is broken into segments or crushed, the
plunger terminating its
downward movement at a distance from the bottom of the recess or at the
predetermined pressure.
The plunger is subsequently displaced from the pill, under the control of the
drive control, and may
be again displaced toward the pill through a second predetermined stroke to
break the pill or pills
into smaller segments. During this second predetermined stroke, the plunger is
again rotated by the
worm and nut drive transmission. The plunger is subsequently again displaced
from the pill
segments, under the control of the drive control, and may be again displaced
toward the pill through
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a third predetermined stroke to ensure that each pill is pulverized by
crushing and grinding into a
fine powder. During this third stroke, the plunger is again rotated by the
worm and drive
transmission.
Preferably an undersurface of the plunger and a bottom surface of the recess
are both
dimpled in order to promote effective crushing and pulverization of the pill.
DESCRIPTION OF THE DRAWINGS
The present invention will be more readily understood from the following
description of a preferred embodiment thereof given, by way of example, with
reference to the
accompanying drawings (Note that the `A' drawings, e.g., Figure 2A, refer to
the first embodiment
and the `B' drawings, e.g., Figure 2B, refer to the second embodiment), in
which:-
Figure IA shows a view in perspective of a pill crusher embodying the first
embodiment of the present invention;
Figure 113 shows a view in perspective of a pill crusher embodying the second
embodiment of the present invention;
Figure 2A shows a view in perspective of the pill crusher of Figure 1A with a
housing removed to show components in the interior of the pill crusher of
Figure 1 A;
Figure 2B shows a view in perspective of the pill crusher of Figure 113 with a
housing removed to show components in the interior of the pill crusher of
Figure 1B;
Figure 3A shows a view taken in vertical cross-section through parts of the
pill
crusher of Figures 1A and 2A;
Figure 3B shows a view taken in vertical cross-section through parts of the
pill
crusher of Figures 1B and 2B;
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Figure 3A(i) shows a view of gears taken in section along the line 3A(i) -
3A(i) of
Figure 3A;
Figure 4A shows a broken-away view, corresponding to parts of Figure 3A, but
with
a plunger displaced downwardly from the position in which it is shown in
Figure 3A;
Figure 4B shows a broken-away view, corresponding to parts of Figure 3B, but
with
a plunger displaced downwardly from the position in which it is shown in
Figure 3B;
Figures 5A(i) and 5A(ii) show broken-away views in vertical cross-section of
parts
of the pill crusher of Figure lA;
Figures 5B(i) and 5B(ii) show broken-away views in vertical cross-section of
parts
of the pill crusher of Figure 1 B;
Figure 6A shows a broken-away view in perspective of parts of the pill crusher
of
Figure IA;
Figure 6B shows a broken-away view in perspective of parts of the pill crusher
of
Figure I B;
Figures 7A and 8A show broken-away views in horizontal cross-section through
parts of the pill crusher shown in Figure IA;
Figures 7B and 8B show broken-away views in horizontal cross-section through
parts of the pill crusher shown in Figure 1B;
Figures 9A(i) and 9A(ii) show circuit diagrams of a control unit in the pill
crusher of
Figure IA;
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Figures 9B(i), 9B(ii) and 9B(iii) show circuit diagrams of a control unit in
the pill
crusher of Figure 1B;
Figure 10A shows a flowchart of a routine followed by the circuit of Figures
9A(i)
and 9A(ii) when the circuit is powered up;
Figure 10B shows a flowchart of a routine followed by the circuit of Figures
9B(i),
9B(ii), and 9B(iii) when the circuit is powered up;
Figure 1 IA shows a flowchart of a routine followed by the circuit prior to
operation
of the pill crusher of Figure IA;
Figure 11B shows a flowchart of a routine followed by the circuit prior to
operation
of the pill crusher of Figure 1 B;
Figure 12A shows a flowchart of a routine followed by the circuit during
operation
of the pill crusher of Figure 1 A;
Figure 12B shows a flowchart of a routine followed by the circuit during
operation
of the pill crusher of Figure 1 B;
Figures 12A(i) - (iv) show flowcharts of subroutines followed by the circuit
during
the operation illustrated in Figure 12A; and
Figures 12B(i) - (iv) show flowcharts of subroutines followed by the circuit
during
the operation illustrated in Figure 12B.
DETAILED DESCRIPTION OF THE INVENTION
In Figures IA and 1B, first and second embodiments, respectively, are shown of
a
pill crusher according to the invention, which is indicated generally by
reference 10 and which has a
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housing 12. In Figure IA of the first embodiment there is shown a
cylindrically-curved paper cup
holder 14 at a rear corner of the housing 12. In Figure lB of the second
embodiment there is shown
a drop handle 11 on the side of the housing 12. There is also a second drop
handle (not shown)
located on the opposite side of the housing 12.
Referring now to Figures 2A and 2B, which show pill crusher 10 with housing 12
removed, it can be seen that the pill crusher has a pair of parallel vertical
side walls 16, between
which extends a platform 18.
In Figure 2A of the first embodiment platform 18 projects forwardly from the
side
walls 16 and is supported on a pair of posts 20 and 21 at opposite front
corners of the pill crusher.
At the rear of the pill crusher, there is provided a low noise electric motor
22 (as seen in Figure 3A)
having a vertical axis.
In Figure 2B of the second embodiment there is provided a low noise electric
motor
22 (as seen in Figure 3B) having a vertical axis, at the front of the pill
crusher.
As shown in Figures 3A and 3A(i) of the first embodiment, the electric motor
22 has
a drive shaft 24, which carries a gear 26 meshing with a gear 28 mounted on a
vertical shaft 30,
which is journaled at its lower end in a base plate 32 and, at its upper end,
in a platform 34 on which
the motor 22 is mounted. A further gear 36 on the shaft 30 meshes with a gear
38 on a shaft 40,
which is also journaled at opposite ends in the base plate 32 and platform 52.
A gear 42 on the shaft
40 meshes, in turn, with a gear 44 mounted on the lower end of a vertical
shaft 46. The shaft 46 is
journaled at opposite ends in bearings 48 and 50. The bearings 48 are mounted
in the platform 34
and 52 at the lower end of the shaft 46, and the bearings 50 are mounted in a
pair of vertically
spaced platforms 54, which extend between the side walls 16.
The upper end of the vertical shaft 46 is connected by a chain and sprocket
drive,
indicated generally by reference numeral 56, to a square-sectioned upper end
portion 55 of a shaft
57 at the upper end of a worm gear 58, which has a vertical axis parallel to
that of the shaft 46.
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The worm gear 58 meshes with a threaded nut 60, which is fixed to the platform
18,
and at its lower end carries a plunger which is indicated generally by
reference numeral 62 and
which is made of nylon or other suitable plastic material.
As shown in Figure 3B of the second embodiment, the electric motor 22 has a
drive
input 24. Inserted into drive input 24 is a drive shaft 25, which carries a
gear 26, which is journaled
at opposite ends in bearings 48, which are mounted at its lower end in a base
plate 32 on which the
motor 22 is mounted and, at its upper end, in a platform 34. The gear 26 is
connected by a grooved
belt pulley drive 56 (as seen in Figure 2B), to a second gear 36, which is
journaled at opposite ends
in bearings 50, which are mounted at its lower end in a base plate 33 and, at
its upper end, in a
platform 35. The gear 36 is carried on shaft 57 at the upper end of a worm
gear 58, which has a
vertical axis parallel to that of shaft 25.
The worm gear 58 meshes with a threaded nut 60, which is fixed to the platform
18,
and at its lower end carries a plunger 62 which is made of stainless steel or
other suitable metal
material.
As shown in Figures 3A and 3B, the plunger 62 co-operates with a receptacle
indicated generally by reference numeral 64, which is pivotally mounted on the
post 20 as described
in greater detail below.
The receptacle 64 has an upwardly-open, frusto-conical recess 66 (as seen in
Figures
2A and 2B), in which a pair of paper cups 68 and 69, are inserted one into the
other (as seen in
Figures 4A and 4B); a body portion 70, which forms the wall of the recess 66;
and a circular plate
72, which is secured by screws (not shown) in the underside of the body
portion 70 and which
forms the bottom of the recess 66.
The plunger 62 has a frusto-conical surface 73, which is complementary in
shape to
the frusto-conical recess 66, and an undersurface 74. The undersurface 74 of
the plunger 62 and the
opposed upper surface 75 of the plate 72 forming the bottom of the recess 66
are both dimpled.
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Referring now to Figure 6A of the first embodiment, the body 70 of the
receptacle 64
has an upstanding front wall 78, an upstanding sidewall 80, which is spaced
from the wall 78 by a
gap 82, and a cylindrically curved wall 84 connecting inner surfaces of the
walls 78 and 80.
A lower end 88 of the post 20 is formed with flat opposite sides 86 so as to
enable
the lower end 88 to slide through the gap 82 into and out of a cylindrical
space within the curved
wall 84. Normally, the lower end 88 of the post 20 is located within this
cylindrical space, so that
the cylindrical wall 84 and the lower end 88 of the post 20 form a readily
releasable pivotal
connection between the receptacle 64 and the pill crusher 10.
By pivoting the receptacle 64 about the post 20 into the relative positions in
which
they are shown in Figure 6A of the first embodiment, the receptacle 64 can be
released from the
post 20 and, thus, from the pill crusher 10 to enable the receptacle 64 to be
thoroughly cleaned.
Referring now to Figure 6B of the second embodiment, the body 70 of the
receptacle
64 has an upstanding front wall 78, with a cylindrically curved end 84. An
opening located on the
undersurface of the upstanding front wall 78 at the cylindrically curved end
84 slides onto post 20 to
form a readily releasable pivotal connection between the receptacle 64 and the
pill crusher 10.
By pivoting the receptacle 64 about the post 20 into the relative positions in
which
they are shown in Figure 6B of the second embodiment, the receptacle 64 can be
released from the
post 20 and, thus, from the pill crusher 10 to enable the receptacle 64 to be
thoroughly cleaned.
In Figures 1A and 1B, the receptacle 64 is shown in its closed position, in
which the
body 70 of the receptacle 64, with the recess 66, is located within and
concealed within the housing
12. By pivotation about the post 20, the receptacle 64 can be displaced into
an opened position, in
which it is shown in Figures 2A and 2B and in which the recess 66 is
accessible at the exterior of
the housing 12.
The walls 78 (and 80 in the first embodiment) close the opening in the housing
12
when the receptacle 64 is in its closed position during the crushing of the
pill, and therefore airborne
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dust levels are reduced during the crushing operation and, also, the operator
of the pill crusher 10 is
prevented from inserting his or her fingers inside the housing 12.
While the pill crusher is in use, it can, for convenience, be mounted on the
working
surface of a medication cart, which is pushed from room to room by a nurse and
used for preparing
medications for administration to patients. For that purpose, the pill 91 is
placed between the two
paper cups 68 and 69, as seen in Figures 4A and 4B, in order to minimize
contamination of the
plunger 62. The pill is then pulverized, as described below, and the top cup
69 is then removed from
the bottom cup 68 to allow the powder produced by the pulverization to be
mixed with juice or food
for consumption by the patient.
To initiate the grinding operation in the first embodiment, the operator is
required to
simultaneously press buttons 90 which are located at opposite sides of the
housing 12. The operator
is therefore required to use both hands to press these buttons 90, so that the
operator's hands must
be located away from the vicinity in which the crushing operation occurs. As a
further safety
measure, the electric motor 22 cannot be energized unless the receptacle 64 is
in its closed position,
in which the recess 66 is located below the plunger 62 and the opening in the
housing 12, through
which the receptacle 64 pivots between its closed and opened positions, is
closed by the walls 78
and 80 of the receptacle 64, thereby preventing access to the interior of the
housing 12 and, in
particular, at the region of the plunger 62.
To initiate the grinding operation in the second embodiment, the operator is
required
to press button 90 which is located at the top of the front of the housing 12.
As a safety measure, the
electric motor 22 cannot be energized unless the receptacle 64 is in its
closed position, in which the
recess 66 is located below the plunger 62; and the opening in the housing 12,
through which the
receptacle 64 pivots between its closed and opened positions, is closed by the
wall 78 of the
receptacle 64, thereby preventing access to the interior of the housing 12
and, in particular, at the
region of the plunger 62.
In the first embodiment, to ensure effective pulverization with the pill 91
located
between the paper cups 68 and 69, the plunger 62 is first moved downwardly to
initiate the crushing
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of the pill 91 as seen in Figure 4A. The plunger 62 is then raised by a small
distance, as seen in
Figure 5A(i), in which this distance has been exaggerated to facilitate the
illustration of the
operation, after which the plunger 62 is then twice lowered again, as seen in
Figure 5A(ii), and
raised again, to pulverize the pill 91. As the plunger 62 is lowered, it is
simultaneously rotated.
Finally, the plunger is raised into a "Park" position, in which it is shown in
Figure 3A, to enable the
paper cups 68 and 69 to be withdrawn from the pill crusher 10.
In the second embodiment, to ensure effective pulverization of the pill 91
located
between the paper cups 68 and 69, the plunger 62 is moved downwardly to
initiate the crushing of
the pill 91 as seen in Figure 4B. As the plunger 62 is lowered, it is
simultaneously rotated. The
plunger is raised into a "Park" position, in which it is shown in Figure 3B,
to enable the paper cups
68 and 69 to be withdrawn from the pill crusher 10.
The grinding of the pill is promoted by the rotation of the plunger 62 and by
the
dimpling of the opposed surfaces of the bottom of the receptacle 64 and the
underside of the plunger
62.
The operation of the first embodiment of the pill crusher 10 is controlled by
a control
circuit shown in Figures 9A(i) and 9A(ii), which includes a microprocessor 100
which is a PIC 16 F
870 microprocessor sold by Microchip Corporation, a voltage regulator 101 and
a LCD 102
provided with a negative voltage generator 104. Through gates GI, G2 and G3,
and through an H-
circuit comprising transistors Ti - T6, the microprocessor 100 controls
operation of the motor 22, as
described below.
When this circuit is energized by connection to its battery, the
microprocessor 100
performs the routine shown in Figure IOA of the first embodiment by setting up
its internal
functions and then initializing the LCD 102, which then displays the word
"INITIALIZING".
LEDs T9 and T10 are then energized. The LEDs T9 and T 10 are provided on a
post
92 (as seen in Figure 2A) and co-operate with a pair of photodiodes D2 and D3
for sensing the
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vertical position of the top of the shaft, the photodiodes D2 and D3 being
provided on a post 93
parallel to the post 92.
If the plunger 62 is not in its fully raised or "rest" position, the motor 22
is energized
to raise the plunger 62 into this position.
After a one-second delay, a bicolour LED Dl, which is visible at the front of
the
housing 12, is changed to green, and the LCD 102 displays the word "READY".
The microprocessor 100 then cycles through the loop shown in Figure 11 A until
the
pill crusher is operated.
When the pill 91 is inserted with the paper cups 68 and 69 into the receptacle
64, the
receptacle 64 must be moved into its closed position, in which it closes a
magnetically operated
switch S3, to prevent access to the interior of the housing 12 and to
counteract the escape of dust
from the housing during the crushing of the pill 91.
The operator then presses the two buttons 90 on opposite sides of the housing
12 to
close switches Si and S2, which are connected in series with the switch S3.
The closure of the three switches Si - S3 initiates the routine shown in
Figure 12A of
the first embodiment by changing the LED DI to red and performing a battery
health routine,
illustrated in Figure 12A(iv), to ensure that the voltage of the battery
remains sufficiently high.
The LED 102 is then changed to display the word "CRUSHING" and the vertical
position of the plunger 62 is then checked as described above.
If the plunger 62 is not in its fully raised position, the LED D 1 is changed
to yellow,
the motor 22 is started with a soft start as shown by the subroutine of Figure
12A(ii) and the plunger
62 is raised to the fully raised position, the subroutine of Figure 12A(i)
being employed to brake the
motor 22. The LED D1 is then changed back to green.
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With the plunger 62 located in its fully raised position, the motor 22 is
energized by
a soft start as illustrated in the subroutine of Figure 12A(iii), to move the
plunger downward, as
described above, to initiate the crushing of the pill.
When the photodiode D3 senses that the plunger 62 has reached its lower
position,
the subroutine of Figure 12A(ii) is again initiated, after a one-second delay,
to raise the plunger 62.
As shown in Figure 12A, the plunger 62 is then lowered and raised again twice,
so
that the pill 91 is pulverized by three downward strokes of the plunger 62.
However, it has been found that in some cases, two downward strokes of the
plunger
62 are sufficient, and the programming of the microprocessor 100 can be
readily modified to omit
one of the three strokes.
When the crushing of the pill has been completed, the LCD 102 is changed to
display the word "READY" again, and the LED D1 is again changed to green.
The operation of the second embodiment of the pill crusher 10 is controlled by
a
control circuit shown in Figures 9B(i), 9B(ii), and 9B(iii), which includes a
microprocessor 100
which is a PIC 18 F 458 microprocessor sold by Microchip Corporation, a
voltage regulator 101 and
a LCD 102. Through the motor control board (as seen in Figure 9B(ii)), which
consists of a H-
Bridge controller, power MOSFETs, and related discrete components, the
microprocessor 100
controls operation of the motor 22, as described below.
When this circuit is energized by connection to its battery, the
microprocessor 100
performs the routine shown in Figure lOB by setting up its internal functions
and then initializing
the LCD 102, which then displays the word "INITIALIZING".
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The photo-reflective infrared sensor 63 is then energized which allows the
detection
of the position of the plunger. If the plunger 62 is not in its fully raised
or "rest" position, the motor
22 is energized to raise the plunger 62 into this position.
After a one-second delay, a bicolour LED D1, which is visible at the front of
the
housing 12, is changed to green, and the LCD 102 displays the word "READY" as
shown by the
subroutine in Figure 12B(iv), and also displays the battery power with the
words "BATTERY:
xx%" as shown by the subroutine in Figure 12B(iii), where `xx%' equals '100%',
`75%', `50%', or
`25%'.
The microprocessor 100 then cycles through the loop shown in Figure 11B until
the
pill crusher is operated.
When the pill 91 is inserted with the paper cups 68 and 69 into the receptacle
64, the
receptacle 64 must be moved into its closed position, in which it closes a
magnetically operated
switch S2, to prevent access to the interior of the housing 12 and to
counteract the escape of dust
from the housing during the crushing of the pill 91.
The operator then presses the button 90 on the top of the front of the housing
12 to
close switch S I.
The closure of the switch S l initiates the routine shown in Figure 12B by
changing
the LED DI to red. The LED 102 is then changed to display the words "CRUSHING;
PLEASE
WAIT" and the receptacle 64 is verified to be in the closed position, and if
so, the door lock
solenoid 65 is energized to lock the receptacle 64 into position and prevent
opening. If the
receptacle 64 has been moved to the open position, the crushing sequence is
halted, and the LCD
102 is changed to display "DOOR OPEN". Only when the receptacle 64 is in the
closed position
will the crushing sequence be allowed to begin again.
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Upon the success of the above operations, the vertical position of the plunger
62 is
then checked as described above. If the plunger 62 is not in the raised
position, a homing sequence
is initiated to bring the plunger 62 into position.
With the plunger 62 located in its fully raised position, the motor 22 is
energized by
a plunger down routine as illustrated in the subroutine of Figure 12B(ii), to
move the plunger
downward, as described above, to initiate the crushing of the pill.
When the pressure sensor D4 (as seen in Figure 4B) senses that the plunger 62
has
reached the first predetermined pressure, the motor 22 is energized by a
plunger up routine as
illustrated in the subroutine of Figure 12B(i), after a one-second delay, to
raise the plunger 62.
When the crushing of the pill has been completed, the LCD 102 is changed to
display the word "COMPLETE", and the LED D 1 is again changed to green.
Although the particular preferred embodiments of the invention have been
disclosed
in detail for illustrative purposes, it will be recognized that variations or
modifications of the
disclosed apparatus lie within the scope of the present invention.
