Note: Descriptions are shown in the official language in which they were submitted.
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TEST TUBE ORIENTING SYSTEM
FIELD OF THE INVENTION
The present invention relates to a test tube orienting system. In particular,
the present
invention to relates to an apparatus for extracting randomly-oriented test
tubes from a
hopper with a consistent orientation in preparation for automated processing,
including
packaging and automated biological specimen testing.
BACKGROUND OF THE INVENTION
To reduce the cost of testing biological specimens, automated biological
specimen testing
systems have been developed whereby test tubes containing biological fluid are
conveyed
in assembly-line fashion to one or more automated testing stations. Bar codes
labels are
affixed to each test tube to indicate to the testing station the desired test
to be performed.
Each test may involve the separation of the biological fluid into multiple
portions.
Therefore, it is desirable for empty secondary test tubes to be available for
insertion into
the assembly line on demand behind each specimen.
Randomly-oriented test tubes can be purchased in bulk and stored in a test
tube hopper
for use as the secondary test tubes. However, randomly-oriented test tubes are
not
desirable for use in assembly line biologic specimen testing since the test
tubes must be
properly oriented by hand prior to labeling and insertion into the assembly
line. For this
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reason, medical testing laboratories generally purchase packages of pre-
oriented bulk test
tubes for use as the secondary test tubes. Still, pre-oriented test tubes are
expensive since
the test tubes must be pre-oriented and packaged by hand before being shipped
to the
laboratory. Therefore, there is a need for a system which automatically
extracts
randomly-oriented test tubes from a test tube hopper and orients the test
tubes prior to
packaging or specimen testing.
Vibratory bowls are well known mechanisms capable of orienting small parts
from a
vessel containing randomly-oriented parts. Vibratory bowls include a small
open-
mouthed bowl for retaining the randomly-oriented parts, and a discharge
channel
provided adjacent the mouth. The vibratory bowl generally has a saw-tooth
vibratory
waveform which serves to urge the parts from the bowl and along the discharge
channel
with a consistent orientation. However, vibratory bowls are very expensive.
Furthermore, as the radius of the bowl must increase according to the size of
the parts to
be oriented, the cost of a vibratory bowl having a size sufficient for
orienting test tubes
would be prohibitive. Accordingly, there remains a need for a cost-effective
solution for
extracting randomly-oriented test tubes from a hopper with a consistent
orientation.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a system for providing
consistently-
oriented test tubes from a test tube hopper containing randomly-oriented test
tubes. It is
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also an object of the present invention to provide a system for extracting
randomly-
oriented test tubes from a test tube hopper with consistent orientation prior
to labeling
and insertion into an automated biological specimen testing system.
In accordance with these objects, there is provided a test tube orienting
system
comprising a vessel for receiving a plurality of test tubes, and a test tube
transport system
for directing the test tubes out of the vessel. The vessel includes an open
mouth, an
internal cavity communicating with the mouth, and a side wall enclosing the
cavity. The
side wall includes a downwardly inwards sloping channel extending along the
side wall
from the mouth and dimensioned for receiving the test tubes therein. The
transport
system directs the test tubes axially upwards along the channel, and includes
a plurality of
tube supports extending through the channel into the cavity. Drive means are
coupled to
the tube supports for directing the tube supports upwards along the channel
while
progressively retracting the tube supports from the cavity.
In the preferred embodiment of the invention, the drive means comprises a
prime mover
and an endless chain driven by the prime mover, and the tube supports comprise
equidistantly-spaced elongate pins of equal length affixed to the endless
chain. While the
chain is being driven, the pins move upwards through the channel, thereby
driving test
tubes axially upwards against the side wall and along the channel. The chain
lies in a
plane which makes an acute angle with the side wall so that as the pins
approach the
mouth of the vessel, the pins are progressively retracted from the cavity.
Since test tubes
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have a rounded closed end, those test tubes which are oriented with their
closed end down
will fall away from their respective pin as the pin retracts. However, since
the diameter
of the test tube adjacent the open end is greater than at the closed end,
those test tubes
which are oriented with their open end down will remain in contact with the
pin over the
length of the cavity. As a result, all the test tubes which are ejected from
the vessel
mouth will have the same orientation.
BRIEF DESCRIPTION OF THE DRAWINGS
The preferred embodiment of the invention will now be described, by way of
example
only, with reference to the drawings, in which:
Fig. 1 is a perspective view of the test tube orienting system, according to
the invention,
showing the test tube hopper and the test tube transport system;
Fig. 2 is a left side view of the test tube hopper and the test tube transport
system shown
in Fig. 1;
Fig. 3 is a right side view of the test tube hopper and the test tube
transport system; and
Fig. 4 is a front view of the test tube orienting system, showing the upper
portion of the
test tube transport system.
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DETAILED DESCRIPTION OF THE PREFERRED EMBODIIVIENT
Turnin$ to Fig. 1, a test tube orienting system, denoted generally as 100, is
shown
comprising a test tube hopper 102, and a transport system 104 coupled to the
test tube
hopper 102 for extracting test tubes 106 upwards out from the test tube hopper
102.
The test tube hopper 102 has an internal cavity 108 (Fig. 2) for receiving the
test tubes
106, front, right, left and rear sides walls 110, 112, 114, 116 enclosing the
internal cavity
108, and an open mouth 118 communicating with the internal cavity 108 through
which
the test tubes 106 may be deposited into the internal cavity 108. As shown in
Figs. 1 and
2, the front side wal1110 includes a substantially-vertical upper portion 110a
and a lower
portion 110b sloping downwardly inwards from the upper portion 110a for
directing the
test tubes 106 deposited into the test tube hopper 102 towards the rear side
wall 116.
However, it will be appreciated that the test tube hopper 102 need not adopt
the above-
described shape, but may instead adopt other shapes or mechanisms for
directing the test
tubes 106 towards the rear side wall 116.
With reference to Fig. 3, preferably the rear side wall 116 also includes an
upper portion
116a and a lower portion 116b. The upper portion 116a slopes downwardly
inwards from
the open mouth 118. The lower portion 11 6b slopes downwardly inwards from the
junction 116c of the upper portion 116a and the lower portion 11 6b, but at a
steeper angle
than the upper portion 116a, and mates with the right and left side walls 114,
116 at the
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base 120 of the test tube hopper 102. As will be explained, the upper portion
116a and
the lower portion 1 I6b slope downwards at different angles in order to
enhance the
orientation capabilities of the test tube orienting system 100. However, other
means may
be adopted as the footprint of the apparatus dictates.
The rear side wall 116 includes a test tube channel 122 which extends along
and through
the rear side wall 116 from the open mouth 118 and terminating at a point
adjacent the
base 120. The test tube channel 122 is dimensioned such that a test tube 106
will be
seated in the channel 122 a sufficient depth to allow the test tube 106 to
move axially
along the length of the channel 122 without falling through the channel 122
and out of the
test tube hopper 102.
It will be appreciated that as the volume of test tubes 106 occupying the
intemal cavity
108 increases, the force exerted by the mass of test tubes 106 against the
rear side wall
110 can increase to the extent that it may not be possible to extract test
tubes 106 from
the test tube hopper 102. To allow the test tubes 106 to be easily removed
from the test
tube hopper 102 regardless of the volume of test tubes 106 in the test tube
hopper 102,
the test tube hopper 102 includes a novel bulk material conveyancing system.
Turning to
Figs. 2 and 3, the bulk material conveyancing system is shown comprising a
primary
compartment 124 adjacent the front side wall 110, a secondary compartment 126
adjacent
the rear side wall 116 and smaller than the primary compartment 124, and a
dividing wall
128 separating the primary and secondary compartments 124, 126. A channel (not
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shown) is provided between the dividing wall 128 and the right side wall 112
to allow
test tubes 106 to pass from the primary compartment 124 to the secondary
compartment
126.
Those having experience with the conveyancing of bulk materials will recognize
that a
bridge of test tubes 106 can form in the channel between the dividing wall 128
and the
right side wall 112 as test tubes 106 pass from the primary compartment 124 to
the
secondary compartment 126. This bridge can restrict and eventually terminaie
the flow
of test tubes 106 from the primary compartment 124 to the secondary
compartment 126,
and therefore prevent test tube 106 flow out of the test tube hopper 102. To
prevent bulk
material bridges from terminating test tube 106 flow out of the test tube
hopper 102, the
bulk material conveyancing system further comprises an agitator disc (not
shown)
mounted on the shaft 130 (Fig. 3) of an agitator motor disposed below the
lower portion
110b. The agitator disc is mounted flush against the right side wall 112 and
the right side
edges of the lower portion 110b and the rear side wall 116, and includes a
rubberized
layer provided on the surface of the disc adjacent the primary and secondary
compartments 124, 126. In addition, the right side wall 112 includes a cut-out
portion
132 adjacent the lower portion thereof to increase the surface area of the
rubberized layer
exposed to the primary compartment 124 and the secondary compartment 126.
The agitator motor is coupled through control logic to sensors (not shown)
provided in
the secondary compartment 126. When the sensors detect that the volume of test
tubes
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106 in the secondary compartment 126 has fallen below a minimum threshold
level,
indicating possibly the existence of bulk material bridge, the agitator motor
is activated,
causing the agitator disc to rotate. The rubberized layer of the agitator disc
gently
agitates any test tubes 106 in the vicinity of the bulk material bridge,
thereby causing the
bulk material bridge to collapse and allowing test tubes 106 to flow once
again from the
primary compartment 124 to the secondary compartment 126. When the sensors
detect
that the volume of test tubes 106 in the secondary compartment 126 has risen
to the
maximum threshold level, the agitator motor is deactivated to prevent the mass
of test
tubes 106 in the secondary compartment 126 from hindering extraction of the
test tubes
106 from the secondary compartment 126.
With reference now to Figs. 1, 2 and 3, the transport system 104 is shown
comprising an
upper sprocket 134, a lower sprocket 136, and an endless chain 138 directed
around the
upper and lower sprockets 134, 136. A plurality of elongate pins 140 of equal
length are
secured to the endless chain 138. A first chain guide 142 is positioned
adjacent the outer
surface of the rear side wall 116, and extends from the lower sprocket 136 to
the upper
sprocket 134 along a path parallel to the test tube channel 122. A second
chain guide 144
extends from the upper sprocket 134 to the lower sprocket 136 along a line
parallel to the
test tube channel 122, but laterally displaced a distance from the test tube
channel 122.
As will be appreciated, the first and second chain guides 142, 144 guide the
endless chain
138 between the upper and lower sprockets 134, 136 and serve to restrict
unwanted lateral
movement of the endless chain 138.
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As shown most clearly in Figs. 2 and 3, the pins 140 are spaced along the
length of the
endless chain 138, with the distance between adjacent pins 140 being greater
than the
length of the test tubes 106. Preferably, the pins 140 are equidistantly
spaced apart.
When the pins 140 travel along the first chain guide 142, the pins 140
proximate the test
tube hopper 102 extend through the test tube channel 122 and into the
secondary
compartment 126. However, the first and second chain guides 142, 144 lie in a
plane
which makes an acute angle with the lower portion 116b of the rear side wall
116. As a
result, the pins 140 positioned adjacent the base 120 extend more fully into
the second
compartment 126 than the pins 140 positioned adjacent the open mouth 118. On
the
other hand, as will be apparent from Fig. 3, the first and second chain guides
142, 1441ie
in a plane which is parallel to the upper portion 116a of the rear side
wa11116.
Accordingly, the degree of penetration of the pins 140 into the test tube
channel 122,
between the open mouth 118 and the junction 11 6c of the upper portion 11 6a
and the
lower portion 116b, remains constant.
With reference now to Figs. 1, 2 and 4, the transport system 104 is shown also
including
a first test tube guide 146 coupled to the test tube channel 122 at the open
mouth 118, and
a C-shaped second test tube guide 148 coupled to the outlet of the first test
tube guide
146. A test tube labeling station 150 is shown coupled to the outlet of the
second test
tube guide 146. However, it will be appreciated that the test tube labeling
station 150
could be replaced with any other suitable station, such as a test tube
packaging station.
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The first test tube guide 146 extends from the open mouth 118 towards the
upper sprocket
134, bends around the outer circumference of the upper sprocket 134, and
terminates at a
point adjacent the apex 147 of the path taken by the endless chain 138. The
first test tube
guide 146 includes a first guide channel 152 through which the pins 140 extend
into the
first test tube guide 146. The first guide channel 152 is axially-aligned with
and is
dimensionally similar to the test tube channel 122, but has a greater depth
than the test
tube channel 122 so as to allow the test tubes 106 which travel from the test
tube channel
122 to the first guide channe1152 to be more deeply seated in the first guide
channel 152
than in the test tube channel 122. The first test tube guide 146 also includes
a cover 154
which mates with the first guide channel 152 to retain the test tubes 106 in
the first guide
channel 152.
The second test tube guide 148 includes a second guide channel 156 and mating
cover
158, and is displaced a finite distance from the apex 147 of the endless chain
138 path so
as to allow the pins 140 to travel from the apex 147, between the first and
second test
tube guides 146, 148 and along the second chain guide 144. The second guide
channel
156 is dimensionally similar to the fust guide channel 152 and, together with
the mating
cover 158, conveys the test tubes 106, as they are brought to the apex 147, to
the labeling
station 150 under influence of gravity.
As shown in Fig. 4, the upper sprocket 134 is coupled to a motor 160 for
rotating the
upper sprocket 134 in response to demand for test tubes 106. The motor 160 is
coupled
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through control logic to first and second sensors 162a, 162b communicating
with the
second test tube guide 148. When the first sensor 162a detects the absence of
test tubes
106 adjacent the first sensor 162a, the motor 160 is activated, causing the
upper sprocket
134 to rotate and the pins 140 disposed in the test tube channel 122 to be
directed
upwards through the test tube channel 122. Since the test tubes 106 are
directed against
the rear side wall 116 by the mass of the test tubes 106 in the secondary
compartment 126
and by the agitator disc, the pins 140 will engage the test tubes 106
proximate the pins
140 and direct the engaged test tubes 106 axially upwards along the test tube
channel 122.
As will be appreciated, all of the pins 140 will not necessarily be successful
in directing a
test tube 106 along the channel 122.
Since the first chain guide 142 lies in a plane which makes an acute angle
with the rear
side wall 116, the pins 140 will progressively retract from the secondary
compartment
126 as the pins 140 are directed upwards along the test tube channel 122. As a
result, the
lowermost portion of each test tube 106 in the test tube channel 122 will
become
progressively less supported by its respective supporting pin 140. The angle
of incline of
the test tube channel 122, in conjunction with the rate of retraction of the
supporting pins
140, causes a moment to be developed about the longitudinal axis of each test
tube 106 in
the test tube channel 122. The angle of incline of the test tube channel 122
and the rate of
retraction of the supporting pins 140 is selected such that for those test
tubes 106 which
have their rounded closed ends oriented downwards in the test tube channel
122, the
resulting moment is sufficient to eject those test tubes 106 from the test
tube channel 122
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back into the test tube hopper 102. However, for those test tubes 106 which
have their
open ends oriented downwards in the test tube channel 122, the resulting
moment is
insufficient to eject these latter test tubes 106 from the test tube channel
122. As a result,
all of the test tubes 106 which reach the open mouth 118 of the test tube
hopper 102 will
be consistently oriented with their rounded closed ends upwards in the test
tube channel
122. Other mechanisms for producing the moment described above will be
immediately
apparent to those sldlled in art.
As discussed above, it is preferable that the lower portion 116b of the rear
slide wal1116
slopes downwardly inwards from the junction 11 6c at a steeper angle than the
upper
portion 116a. Therefore, as the test tubes 106 in the test tube channel 122
pass the
junction 1 16c, the lower ends of the test tubes 106 are displaced further
from the tips of
the pins 140, further facilitating ejection from the test tube channel 122 of
those test tubes
106 which are oriented with their rounded closed ends downwards. However, it
will be
appreciated that depending upon the available footprint, junction 116c may be
eliminated
and the angle of incline of the test tube channel 122 and the rate of
retraction of the pins
140 may be adjusted to achieve satisfactory results.
Between the junction 116c and the open mouth 118, the degree of penetration of
the pins
140 into the test tube channel 122 remains constant. Accordingly, any test
tubes 106
which pass the junction 1 16c will remain seated in the test tube channel 122.
The test
tubes 106 are then conveyed upwards along the first test tube guide 146 by the
pins 140
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to the apex 147. The test tubes 106 are prevented from falling out of the
first test tube
guide 146 as the test tubes 106 approach the apex 147 by virtue of the mating
cover 154
and the increased depth of the fust guide channel 152.
Once the test tubes 106 reach the apex 147, the endless chain 138 directs the
pins 140
downwards towards the second chain guide 144. However, after the pins 140 pass
the
apex 147, the test tubes 106 are urged from the first test tube guide 146 into
the second
test tube guide 148 and towards the labeling station 150 under influence of
gravity. If the
rate at which the test tubes 106 enter the second test tube guide 148 exceeds
the rate at
which the test tubes are labeled at the l.abeling station 150, the second test
tube guide 148
will fill with test tubes 106. When the level of test tubes 106 in the second
test tube guide
148 reaches the first sensor 162a, the control logic coupled to the first
sensor 162a and
the motor 160 causes the motor 160 to be deactivated and fu.rther upwards
movement of
the pins 140 along the test tube channel 122 to cease.
Since the test tubes 106 are ejected from the second test tube guide 148 into
the labeling
station 140 under influence of gravity, it is desirable that a critical mass
of test tubes 106
be maintained in the second test tube guide 148 to ensure that the test tubes
106 are
ejected into the labeling station 150 with sufficient force to allow for
proper operation of
the labeling station 150. Accordingly, in the embodiment shown in Fig. 4, the
second
sensor 162b is coupled to the labeling station 150 through control logic for
activating the
labeling station 150 once the level of test tubes 106 in the second test tube
guide 148
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reaches the second sensor 162b. However, it will be appreciated that,
depending upon the
applica.tion, the second sensor 162b can be eliminated from the second test
tube guide
148.
The description of the preferred embodiment herein is intended to be
illustrative, rather
than exhaustive of the present invention. Those persons of ordinary skill will
be able to
make certain additions, deletions and/or modifications to the described
embodiments
without departing from the spirit or scope of the invention, as defined by the
appended
claims.
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