U.S. patent number 3,746,211 [Application Number 05/205,266] was granted by the patent office on 1973-07-17 for vibratory quantifying apparatus.
Invention is credited to Warren C. Burgess, Jr..
United States Patent |
3,746,211 |
Burgess, Jr. |
July 17, 1973 |
VIBRATORY QUANTIFYING APPARATUS
Abstract
There is provided a vibratory quantifying or counting apparatus
which includes a vibratable receptacle for parts or individual
items of common geometrical configuration and a discharge opening
leading from the receptacle to a chute system composed of a pair of
chutes. Counting means are provided for coaction with one of the
chutes. Gate means operative in response to the counter means are
provided for diverting any excess over a predetermined quantity to
the other of said chutes.
Inventors: |
Burgess, Jr.; Warren C. (Avon
Lake, OH) |
Family
ID: |
22761513 |
Appl.
No.: |
05/205,266 |
Filed: |
December 6, 1971 |
Current U.S.
Class: |
221/7; 221/13;
453/32; 221/200 |
Current CPC
Class: |
G06M
3/02 (20130101); G06M 7/00 (20130101) |
Current International
Class: |
G06M
3/02 (20060101); G06M 3/00 (20060101); G06M
7/00 (20060101); B65g 051/42 () |
Field of
Search: |
;221/2,9,10,12,13X,2X,156-161,163,167,168,13,7 ;133/8
;194/1H,10,16,9 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Reeves; Robert B.
Assistant Examiner: Kocovsky; Thomas E.
Claims
What is claimed is:
1. A vibratory quantifying apparatus comprising in combination:
a. a vibratable receptacle;
b. means for supporting and guiding the receptacle for oscillatory
movement;
c. means coacting with said receptacle for inducing oscillatory
movement thereof;
d. a discharge opening leading from said receptacle;
e. a pair of downwardly sloped chutes disposed for selective
operative communication with said discharge opening;
f. counting means settable to a predetermined quantity coacting
with one of said chutes;
g. gate means operative in response to said counter means and
coacting between said chutes to divert any excess over said
predetermined quantity to the other of said chutes, said gate means
comprising a plate movable between the chutes and lying in the
plane of the bottom of one of said chutes and movable laterally to
remove a bottom portion of one of said chutes to allow access to
the other of said chutes.
2. A vibratory quantifying apparatus in accordance with claim 1
wherein the vibration-inducing means is electromagnetic.
3. A vibratory quantifying apparatus in accordance with claim 1
wherein the chutes are stationarily mounted.
4. A vibratory quantifying apparatus in accordance with claim 1
wherein said plate includes an opening therein, said opening having
a width for at least a portion thereof equal to the width of the
chute.
5. A vibratory quantifying apparatus in accordance with claim 4
wherein the gate means includes a pair of solenoids on opposite
sides thereof connected to said plate and operating in push-pull
relationship to shift the plate laterally.
6. A vibratory quantifying apparatus in accordance with claim 1
wherein at least one of said chutes includes a light source and a
light-sensing member in opposed relationship and intersecting the
path along said chute.
7. A vibratory quantifying apparatus in accordance with claim 6
wherein said light means is disposed across the width of said chute
and downstream from said gate.
8. A vibratory quantifying apparatus in accordance with claim 1
wherein the vibratable receptacle comprises a circular bowl having
upstanding walls and a closed bottom and a spiral trackway
extending from the bottom upwardly along the upstanding wall toward
said discharge opening.
9. A vibratory quantifying apparatus in accordance with claim 8
wherein the discharge opening includes a lip having a sloped
surface for smooth transition into said chutes.
10. A vibratory quantifying apparatus in accordance with claim 8
wherein the sloped surface of the lip is tangential to the surface
of the trackway.
11. A vibratory quantifying apparatus in accordance with claim 8
wherein the trackway includes notch means for limiting the width of
the track.
12. A vibratory quantifying apparatus in accordance with claim 1
wherein the means for supporting and guiding the receptacle include
a base and a plurality of leaf springs extending between the base
and the receptacle.
13. A vibratory quantifying apparatus in accordance with claim 12
wherein the receptacle is a circular bowl and wherein the springs
are disposed circumferentially between the bowl and the base.
14. A vibratory quantifying apparatus in accordance with claim 12
wherein the bottoms of said chutes are sloped downwardly from said
bowl toward the plane of said base.
15. A vibratory quantifying apparatus in accordance with claim 14
wherein the bottoms of the chutes are sloped downwardly from
20.degree. to 45' to the plane of said base.
16. A vibratory quantifying apparatus in accordance with claim 1
wherein the chutes comprising said pair are disposed one above the
other.
17. A vibratory quantifying apparatus in accordance with claim 16
wherein the bottom of the upper chute is flat and laterally sloped
relative to the horizontal.
18. A vibratory quantifying apparatus in accordance with claim 16
wherein each of the chutes comprises a channel having parallel
upstanding walls and a planar bottom.
19. A vibratory quantifying apparatus in accordance with claim 18
wherein the angle of the lateral slope to the horizontal is from
5.degree. to 15.degree..
Description
BACKGROUND OF THE INVENTION AND PRIOR ART
The present invention relates to apparatus for determining a
numerical quantity of items or articles of similar geometric
configuration. More specifically, the present apparatus finds
specific utility as a means for counting drugs in the form of pills
or capsules. The invention will be discussed, therefore, in
reference to this particular utility although it will be clearly
understood that the principles of this invention are applicable as
well to the counting of parts such as transistors, washers, bolts,
other mechanical devices, closures, etc.
In the dispensing of pills or capsules pursuant to order or
prescription, the druggist or pharmacist is familiarly seen pouring
a quantity of the pills or capsules from a supply container into a
counting tray provided along one marginal edge with a
semi-cylindrical depression having a funnel-shaped portion at one
extremity thereof and a closure at the opposite end thereof, and a
hinged cover for mating coaction with the plate. When the hinged
portion is closed, a closed tubular body is formed having a funnel
portion at one extremity. In using the device, a quantity of pills
in excess of that desired is poured onto the plate portion and with
a knife or other suitable instrument, the pharmacist counts out the
desired number of pills and moves them into the semi-cylindrical
depressed portion of the tray. When the desired number is reached,
the hinged portion is closed over the pills confined in the
depression, the balance of the unused pills then being returned to
the supply container by pouring over a suitably formed lip on the
opposite marginal edge of the tray. Thereafter, the tray is
inverted and the counted pills discharged through the funnel
portion of the tube into a prescription bottle or container. While
this operation is simple enough in itself, when performed many
times in the course of the day, it becomes excessively
time-consuming.
The present invention provides an automatic, accurate and rapid
means for dispensing a predetermined quantity of pills or capsules
(or other parts having a uniform configuration) as well as a means
for counting such items as will be explained hereinafter.
The present invention combines in a unique manner the principles of
a vibratory parts feeding apparatus, digital counting means,
preferably of electronic operation, and novel chute and gating
means. Vibratory parts feeders utilizing a fabricated or cast
vibratable receptacle formed, for example, of a generally circular
bowl having upstanding walls and a spiral track leading from the
bottom upwardly along the wall surface to a discharge point are
well known. In general, these devices are mounted upon a plurality
of leaf spring elements which serve to support and guide the
receptacle for vibratory movement along a path. Vibration may be
induced by electromagnetic means or by pneumatic means, or by
mechanical means. A typical example of a pneumatically driven
vibratable receptacle of the type described is shown in my U.S.
Pat. No. 2,985,280 dated May 23, 1961. A further example of a
bowl-type parts feeder utilizing, however, an electromagnetic drive
means is shown in U.S. Pat. No. 2,799,383.
Solid-state electronic predetermining counters are well known and
readily available on the market. While the structure of these
devices forms no part of the present invention and the details
thereof will not, therefore, be discussed, the location of the
counting means after the gating means is believed unique in
unit-counting devices.
The chutes and their arrangement in the present invention are novel
in combination with the gate means for diverting parts or items or
pills after a predetermined figure has been reached. Also, there is
provided a novel bowl exit having a sloped side delivery to provide
controlled initial start of the items or pills into the chute
structure. To control the discharge of items or pills a novel notch
in the spiral track is provided having a geometry able to reduce
the items or pills to a single file over a substantial range of
part diameters or shapes, e.g. disc-type pills and capsules over
the size ranges in which each type is currently available.
BRIEF STATEMENT OF THE INVENTION
Briefly stated, the present invention is in a vibratory quantifying
apparatus which comprises in combination a vibratable receptacle,
means for counting associated with a discharge chute, and gate
means responsive to the counting device for diverting any excess
over a predetermined quantity to another chute. More particularly,
the vibratable receptacle includes means for supporting and guiding
the receptacle for oscillatory movement. Means are provided for
inducing vibration of the receptacle whereby items deposited in the
bottom of the receptacle are moved along a path to a discharge
point. In the course of movement along the path, novel notch means
are provided to assure a single file of parts to be counted. The
discharge leading from the vibrating receptacle is located with
respect to a pair of stationary chutes disposed for selective
operative communication with the discharge opening. Gate means
coact between the chutes and in response to the counter means
located after the gate means so that when the predetermined figure
set in the counter has been reached, the gate is actuated and any
excess over the predetermined quantity is diverted into the second
chute. In the case of the dispensing of pills, the first chute may
lead to the prescription bottle, and the second chute diverges and
leads to the supply bottle.
In a preferred embodiment, the chutes are in superimposed
relationship for at least a part of the pathway, and they are
desirably of generally U-shaped cross-sectional configuration
having upstanding sidewalls and flat bottom surfaces. The gate is a
plate-like member disposed between the chutes and forming a movable
bottom portion of the upper chute way. An opening is provided in
the movable plate such that when the plate is moved laterally in
response to the electronic counting apparatus, the movable bottom
portion of the upper chute is withdrawn, and the pills are allowed
to fall through the opening into the second chute.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an illustration in perspective of a counting apparatus in
accordance with the present invention showing an arrangement
suitable for use in counting pills or capsules. The chutes are
shown leading first to one container and secondly to a supply
container.
FIG. 2 is an illustration of the apparatus shown in FIG. 1 with the
cover and electronic counting apparatus removed and showing the
details of the vibratory parts feeding apparatus, the discharge
opening, the pair of chutes, and the gate apparatus coacting
therebetween.
FIG. 3 is a front view of the gating and counting apparatus shown
in FIG. 2 and showing a preferred disposition of the chutes for
best results.
FIG. 4 is a top view on an enlarged scale of the apparatus shown in
FIG. 2.
FIG. 5 is a fragmentary cross-sectional view of the apparatus shown
in FIG. 4 as it appears in the plane indicated by the lines 5--5 in
FIG. 4.
FIG. 6 is a fragmentary elevation of a portion of the trackway as
it appears in the plane indicated by the line 6--6 in FIG. 4.
FIG. 7 is a fragmentary cross-section through the discharge opening
showing the transition from the vibratory bowl to the stationary
track.
FIG. 8 is a fragmentary portion of a trackway showing the mode of
determining notch geometry.
FIG. 9 is an edge view from the inboard side of the trackway of the
portion shown in FIG. 8.
DETAILED DESCRIPTION OF THE DRAWINGS
Referring now more particularly to FIG. 1, there is here shown a
pill-counting apparatus embodying the principles of the present
invention. There is illustrated a cover 10 formed of sheet metal or
plastic, for example, having an opening 12 adapted to display the
selector and number-exhibiting panel 14 of a commercially available
electronic predetermining counter 16. The cover 10 may be provided
with a hinged clear plastic or glass cover 18 having a wide mouth
funnel 20 positioned therein for admission of items to be counted
into the vibratable receptacle just beneath the funnel 20. The
hinged glass or plastic cover when opened allows ready access to a
bowl 30 for cleaning purposes. The cover 10 and funnel 20 are
optional. Emerging from the forward wall of the cover 10 is an
upper chute 22 and a lower chute 24. Upper chute 22 has disposed in
pill-receiving position a suitable container 26, for example a
graduated container with markings indicating the size of the
prescription bottle required. The chute 24 is positioned above
another container 28, which may be a supply container. Chutes 22
and 24, as will be explained in greater detail hereinafter, are
isolated from each other.
FIG. 2 is a further illustration in perspective with the shroud or
cover 10 and funnel 20 removed along with the electronic counting
device 16 to reveal a parts feeder bowl 30 of generally cylindrical
configuration having a conically shaped bottom 32 and a spiral
trackway 34 leading from the bottom 32 upwardly along an upstanding
wall 36 toward a discharge opening 38 adjacent the top marginal
edge 40 of the upstanding wall 36. The bowl 30 is integral with or
secured to a mounting base 42. The mounting base 42 is supported on
a plurality of spaced, circumferentially located springs such as
spring 48 which serves as means for supporting and guiding the
receptacle or bowl 30 for oscillation along a given path. The
springs 48 are of conventional design and secured to the mounting
base 42 and to a base 50 by conventional means, such as a mounting
lug 52. Usually there are provided four spring stations composed of
lugs, such as lug 52, integrally cast with or secured on the
mounting base 42 and on the base 50 at 90.degree. intervals. The
springs are bolted to the lugs which are sloped (as shown in FIG.
2) a suitable angle such as 75.degree. to the horizontal. In
designing this apparatus, it is desired that weight be minimized
insofar as possible. Thus, integrally cast spring mounting lugs are
preferred, for example.
To achieve accurate counting, it is desired that the items to be
counted are presented at the discharge outlet 38 in single file. To
the achievement of this objective, the trackway 34 is provided with
tooling whereby the succession of items moving along the track is
reduced to a single file. Such tooling may be very inexpensive as
is the novel notch 118 hereinafter described.
The novel discharge opening 38 and its configuration is important
if it is desired to minimize undue bouncing of the parts as they
leave the vibrating bowl in single file, or one at a time, and
enter into a relatively stationary chute portion. As is best shown
in FIG. 4, the upstanding wall portion 36 is desirably flared
outwardly adjacent the opening 38 to facilitate the transition
movement of the parts, for example pills 54, from a circular path
to a linear path. It is desired to prevent extraneous unstable
movement of the parts 54 beyond the flared portion before entry
onto a stationary slide portion 56 which is secured to or integral
with the chute 22. If on leaving the vibrating bowl the pills 54
impact against any obstacle such as the vibrating edge 58 (FIG. 7),
an instability may be imparted to the pill 54 that may interfere
with the accuracy of the count. As shown in FIG. 7, the stationary
discharge slide portion 56 is desirably tangential to the
downwardly curved trackway portion 39 which in use is vibrating.
The lip or edge 41 is desirably located such that it is even with
or slightly above (0.0000 to 0.002 inch) the leading edge 43 of the
stationary bottom portion 56 of chute 22.
Also shown in FIG. 2 are the pair of chutes 22 and 24 which are
disposed for selective operative communication with the discharge
opening 38 and the stationary slide portion 56 (FIG. 7). Chutes 22
and 24 are sloped downwardly at an angle to the horizontal as best
shown in FIG. 5. This angle is desirably approximately
22.5.degree.. The angle itself is not critical except insofar as it
is capable of causing acceleration of the parts 54 as they move
downwardly along the chute. For most purposes, an angle of from
15.degree. to 45.degree. is useful. The parts as they leave the
discharge opening 38 are often quite close together, and for
purposes of accuracy in detection for counting purposes, it is
desirable that the parts 54 be spaced farther apart. A 22.5.degree.
slope has been found to be satisfactory for this purpose.
In a preferred embodiment as shown in FIGS. 2 and 3, the chutes 22
and 24 are in superimposed relation, one above the other. Chutes 22
and 24 preferably, although not essentially, have a generally
U-shaped cross-section with a flat bottom. Thus, in chute 22 the
channel is formed by upstanding parallel walls 60 and 62 joined
along their lower marginal edges by a flat bottom portion 64. In
like manner, the channel of the lower chute 24 is formed by
upstanding walls 66 and 68 joined together by bottom portion 70. It
has also been found that the lower chute 24 should be somewhat
deeper than chute 22 to minimize the chances of any parts or items
falling through the gate (hereinafter described) and bouncing back
up into chute 22. While the paths of chutes 22 and 24 adjacent the
discharge opening 38 coincide with one another, they diverge
approaching their distal extremities indicated at 72 and 74,
respectively. The extent of divergence is, of course, optional; but
it must be sufficient to enable separate collection of the counted
parts or pills 54 and those to be returned to the supply.
The chutes 22 and 24 are supported from a base plate 76 by means of
a bracket 78. The base plate 76 also underlies the base 50 on which
the vibratable receptacle 30 is supported. As indicated above, the
chutes are "relatively" stationary with respect to the vibrating
receptacle. Because the base 50 is of finite mass, it will move
slightly in response to vibratory impulses imparted to the
vibratable receptacle 30 by the vibratory drive means, be they
pneumatic, electromagnetic, or mechanical, or any combination
thereof. Thus, slight movement of the base 50 will be transmitted
through the base plate 76 to the bracket 78. The stationary slide
portion 56 is an extension of the bottom portion 64.
FIG. 5 shows in cross-section the chute assembly including
superimposed chutes 22 and 24. The bottom 70 of chute 24 is
continuous from a position spaced from and beneath the vibrating
slide portion 56 to the distal extremity 74. The bottom 64 of chute
22 is continuous for only a portion of the pathway from the distal
extremity 72 toward the discharge opening 38. A portion 56 of
bottom 64 is a continuation thereof and is tangential to the
trackway portion 39 as above described. An intermediate portion of
the bottom 64 is cut out to provide an opening 80 (FIGS. 2 and 3).
This portion is replaced in a preferred embodiment with a sliding
gate 82 which is also provided with an opening 84 of substantially
equal size to the opening 80. Gate 82 is operated by means of
conventional solenoids 86 and 88 mounted upon a suitable plate 90
by means of brackets 92 and 94, respectively. Suitable guideways,
such as gibs 96 and 98 fastened to each other by a suitable plate
100, control the path of movement of gate 82. Such gibs may be
stamped from the plate 100 itself as a convenient mode of
fabrication of this part. Solenoids 86 and 88 operate in opposing
relation and are secured to the gate 82 by any suitable means such
as pins 104 and 106. When solenoid 86 is energized, solenoid 88 is
simultaneously deenergized and the normal position of the gate is
as shown in FIG. 4 during the counting operation. When the
predetermined number dialed into the predetermining counter 16 is
reached, solenoid 88 is activated and solenoid 86 deactivated,
holding the gate to the position shown in dotted lines in FIG. 4
and disposing the opening 84 fully across the space between the
upstanding walls 60 and 62 of upper chute 22. Pills 54 then fall
through the opening 84 into the lower chute 24 for return to a
supply vessel 28. As is best shown in FIG. 4, the disposition of
the gate 82 during the counting operation is desirably fully
closed. The combination of a properly designed trackway 34 with
tooling as later described and a slope in the discharge surface 39
sloping from tangent to track surface 34 to tangent to the slope of
chute surface 56 provides reliable counting. Generally, such slope
is in the range of from 5.degree. to 15.degree.. The purpose of
these design parameters is to ensure spacing with precise
acceleration to minimize instability of the pills 54 or piling up
of the pills 54 in traversing the chute 22 and ensure that they
will be reduced to a single file for accurate counting. The sensing
device, hereinafter described, will therefore not be led into error
by two pills moving side by side along the chute 22.
Counting occurs in upper chute 22. In the embodiment shown in the
drawings, counting is conveniently and accurately effected by
intercepting a light beam. Thus, there is provided as shown in FIG.
4 a light source 121, e.g. an electric light bulb, and sheathed
electric wires 108, the assembly being supported in mounting block
109. Instead of a bulb being located for transmission of light
through the sidewall 60, the light may be conducted thereto by
means of light conductors, e.g. a plexiglass light conduit or a
fiber optics conduit. A light receptor opening 114 is provided in
the sidewall 62 of upper chute 22. The disposition of the light
source 121 and the receiver 122 (which may be a photoelectric cell)
is such that even the thinnest pills or items traversing the chute
22 will intercept enough of the light beam to activate the
photocell located behind the opening 114. The impulse from the
photocell is carried to a convenient connection box 112 by a
conduit 110. Mounting blocks 109 and 111 are in turn supported by
the plate 90.
Referring now more particularly to FIGS. 2, 3, and 5, it will be
observed that the plate 90 and the parts associated with and
mounted thereon are disposed at a slight angle which, for most
purposes, is between 5.degree. and 15.degree., for example
10.degree.. This provides, therefore, a lateral slope to the bottom
portions 64 and 70 of chutes 22 and 24, respectively (see FIGS. 2
and 5). Such a disposition of the bottom of the upper chute 22 in
particular forces the items or pills 54 to move by gravity toward
the upstanding wall 62 in which the light receiver opening 114 is
disposed. This provides for a more nearly accurate count. The width
of the chute 22 or chute 24 is determined, of course, in large
measure by the size of the items or pills being counted. An
important consideration affecting the accuracy of the apparatus is
the length of the straight section between the exit surface 39 and
the opening 84 in the plate 82. This portion which is identified as
56 in FIG. 7 is considered as having a length "l" and has an
influence on the length of the opening 84 in the gate plate 82. If
too great a distance is traveled by the item being counted, it will
accelerate to a relatively high speed and, therefore, require a
much greater length of the opening 84.
The length of the straight section or portion 56 between the
surface 39 at the end of the vibrating trackway 34 and the opening
84 in the plate 82 is an important consideration. As will be
pointed out hereinafter more particularly, it influences the length
of the opening 84 in the gate 82. If too great a distance is
traveled over the portion 56 and/or the slope is quite steep, the
items being counted accelerate to a higher speed and therefore
require a much greater length of opening 84 to fall through due to
their flatter trajectory. Thus it is desirable for purposes of
practical size in installation for use in pharmacies, for example,
that the length of the stationary portion 56 should be held to a
minimum. For general purposes, the ratio of the length l to the
length "L" (the length of the opening 84) is approximately 1:4. In
a typical embodiment, the length of the portion 56 is 5/8 inch.
As previously indicated, the edges encountered by the part or pill
as it moves down the pathway from the vibrating bowl exit 38 and
through the chute 22 are important. These edges may cause
instability in the parts or pills and therefore could adversely
affect the accuracy of the count. Thus, the edge of the portion 56
of the bottom 64 which is first encountered by the part should be
absolutely tangential to or preferably slightly below the adjacent
edge of the surface 39. As the part leaves the portion 56 and
enters onto the upper surface of the movable gate 82, this surface
should be absolutely in the same plane as the portion 56 or
preferably slightly below the plane of the portion 56. In practice,
there will always be a certain amount of freedom of movement of the
gate in a slot such as provided by gibs 96 and 98. Thus, it is
advantageous to place a small spring (not shown) bearing down upon
the edge of the plate 82 closest to the portion 56, and a small
spring bearing up on the edge of the plate 82 farthest away from
the bowl. This provides assurance of the elimination of instability
introduced by reason of a part striking an edge that enables the
provision of a practical high production design and a high degree
of accuracy. Normally, accuracy can be achieved in the range of
from 0.2 to 1.5 percent for shapes with inherent instability such
as spheres that roll and ovals that slide and bounce in an
irregular fashion.
It is important that there be acceleration of the parts or pills 54
as they move down the stationary exit chute structure. This causes
the parts to space themselves apart from each other for more
accurate counting. It is also desirable to use a photocell which
has a wide band of light-to-dark response. Such devices are capable
of detecting any change in the intensity of the light. If the band
is narrow, then it requires considerable care to prevent input from
external transient signals which may cause count irregularities. It
has also been found that another consideration affecting the
accuracy of the count is the depth of the lower chute 24. The
chutes are normally disposed at an angle in the range of from
20.degree. to 45.degree. to the horizontal. Because of the nature
of some parts, there is a problem of bouncing of the parts from the
bottom of the lower chute 24 and, in some cases, a part may bounce
back up through the gateway opening 80 onto the bottom 64 of the
main chute 22. If the depth of the lower chute is inadequate, this
may create a problem in the accuracy of the count.
An unusual factor in this counting circuit with regard to other
counting circuits is the fact that the counting system is located
below the gating or after the gating mechanism. In other circuits,
it has been the reverse--the counter has been located immediately
ahead of a diverter or some other means for diverting the parts
that have been counted. Because of the extreme speed available in
solid-state counting and solid-state switch gear for energizing and
deenergizing solenoids, it has been found possible to place the
light path (114 - 116) in such close proximity to the botom edge of
slot 84 that, for the most part, the pill or capsule which reaches
the preset count and triggers the counting system to shift the
solenoids actually actuates the circuit while it is still in a
position of instability with regard to the edge of the slot 84
farthest from the bowl. In other words, if the gate 82 were
activated instantaneously, this pill or capsule would continue on
past the light path only because of its speed, inertia, and
trajectory. A part following closely behind this part would
therefore fall through the opening 84. To place the light source
before a diverter or opening would mean that the speed with which
the parts traverse the chute would become a very critical part of
the calculation and would severely limit the accuracy obtainable
with the mechanism. Also, diverters often crush items as they are
passing from one chute entrance to another. This creates a design
problem. When the accuracy of speed of movement of parts down the
chute becomes an important factor, the mere change in atmospheric
humidity from one day to another can cause problems. Thus there is
provided a unique relationship of gating and light path. The
effectiveness of this relationship is, of course, enhanced with the
recently developed high speed solid-state counting equipment. High
speed solid-state switch gear equipment coupled with the improved
counting equipment and the location thereof also improves the
reliability.
In operation, then, a pharmacist desiring to count out a
predetermined number of pills in the filling of a prescription and
utilizing a device in accordance with the present invention will
dial into the predetermining counter a number, for example 100. He
will then discharge into the bowl 30 a number of pills in excess of
100. He will then turn on the electromagnetic vibration-inducing
device, causing the pills resting on the conical bottom 32 to enter
onto the trackway 34 for movement upwardly therealong in a known
manner to the discharge gate 38. A notch 118 is formed in the
trackway 34 adjacent the discharge opening 38. The fixed notch 118
is shaped and sized to be effective for any diameter pill 54 which
will be counted by the device. If the pills should traverse the
track 34 in a side-by-side relation as shown in FIG. 4 as 54a and
54b, pill 54b will drop off the trackway through the notch 118, and
only a single file of pills 54 will progress past that point. Pill
54b will be returned to the supply in the bottom 32 of the bowl 30
for recycling. The width of the track 34 as it appraches the
discharge opening 38 is also calculated to be insufficient to
support two of the largest diameter pills to be metered by the
device.
In FIGS. 8 and 9 there is shown in several positions a large disc
representing a typical pill, for example, and having diameter 2R.
With the disc tangential to the side surface which is the vertical
wall 36 of the bowl 30, the disc tangential points a and b and
surface point 0 are located. A center line of the disc parallel to
the wall through ab locates the geometric balance points of this
disc. Angle AOB is described by drawing lines through aO and bO.
This angle becomes one theoretical limit for the extremities of the
notch 118. Now, two discs X and Y are drawn side-by-side and
against the side surface 36, and a third disc Z is drawn with the
center of the disc Z on a line bQ perpendicular to the wall 36 and
passing between discs X and Y at point b. This is an arbitrary
selection of what might be present on the track and might desirably
be eliminated with regard to parts passing down the track in
side-by-side relation. The disc with diameter r is then drawn
tangential to the other two discs X and Y with the center of the
disc on the center line bQ mentioned above. Moving this disc across
so the center lies on the center line OP of the original disc X
passing through O and perpendicular to the wall 36, one is able to
describe through the balance points c and d of the disc the angle
COD which works out to be approximately 42.degree.. This has been
found to be a good practical lower limit for the included angle of
the notch 118. For purposes of fast dropping and elimination of
parts passing along the trackway 34 in side-by-side relation, it is
advisable to approach the 90.degree. angle AOB as closely as
possible. However, since the trackway 34 is a vibrating surface,
and the transient imbalances set up on convex surfaced discs
(pills) do not permit approaching AOB exactly, experimental work
has indicated that something in the order of EOG is practical for
the included angle of notch 118. This works out to be about
70.degree.. Other practical considerations dictate that it is
advisable to cut the notch short and run a line across at a
distance from the wall equal to the minimum diameter 2r of the
smallest discs divided by two plus a little something extra. This
is also shown in FIG. 8. It is clear from this construction that
almost any ratio of small to large diameter may be handled by the
notch 118. Actually, a track of one-inch width is found capable of
handling a range in diameters of approximately 20 to 1. The center
line or center of balance of the largest part would be slightly
inboard of the edge of the track with the small part of a disc
hanging out over the edge. And yet, no technological knowledge on
the part of the operator is required nor is any expensive
adjustment feature such as has been commonly used prior to this.
The depth h of the notch 118 is desirably about one-fourth the full
width at the inboard edge of the trackway 34. This depth is not
critical since any depth is sufficient whereby edges ME and NG
create a sufficient instability in the undesired part or pill to
cause it to fall off the trackway 34 and allow a single file to
pass by notch 118.
It has also been found that the notch 118 aids in the removal of
capsules which are traversing the trackway 34 in side-by-side
relation. However, it is quite normal to find that capsules tend to
align themselves in a single file well in advance of arrival at the
discharge opening 38 due to the vibratory effects imposed upon the
capsules by the vibrating surfaces of the bowl.
After depositing into the bowl an excess over the predetermined
number 100, the druggist or pharmacist activates the
electromagnetic vibration-inducing device causing the pills to
traverse the trackway toward the discharge opening 38. As indicated
above, the pills encounter a cut-out obstacle in the trackway 34 so
that only a single file of pills or capsules passes the notch 118.
As the pills begin to move through the discharge opening 38 onto
the upper chute 22, the gate 82 is in the closed position as shown
in FIG. 4. Pills cascade down over the sloped portion 56 onto the
surface of the gate 82 and, because of the lateral slope of the
gate and the bottom portion 64 of the upper chute 22, tend to
assume a position along the sidewall 62 of chute 22. Also, because
of the downward slope of approximately 22.degree., the pills 54 are
accelerated along the chute and thus become spaced apart. The
counter apparatus 16 is adapted and arranged by conventional means
so that when the number of impulses sensed by the light-sensing
means 122 reaches the predetermined number, for example 100, then
the solenoid 88 is actuated to drive the gate 82 so that the
opening 84 lies fully across the bottom of the chute 22. Pills 54
now representing an excess over the predetermined number fall
through the opening 84 onto the bottom 70 of lower chute 24 and are
thus diverted into a storage receptacle such as receptacle 28.
While the pills are traversing the bottom 64 of chute 22, they are
directed to a separate receptacle such as receptacle 26 in FIG.
1.
The speed of operation is such that a quantity of 100 pills can
easily be counted in as little as five seconds. The usual time is
about thirty seconds. In the meantime, any excess is being diverted
back into the supply vessel 28.
It is also possible to use the apparatus for the purpose of
counting the number of units in a supply vessel. Thus, if a number
is inserted into a display counter which is well in excess of the
anticipated number of pills in the supply container, a counter
equipped with display tubes will record digitally and visually the
number of interruptions of the light beam, each interruption
corresponding to one unit. Where the predetermined number exceeds
the anticipated number in a given container, the gate 82 will
remain in a position enabling the counting of the parts rather than
isolation of a predetermined number of parts.
* * * * *