Fluent material handling – with receiver or receiver coacting mea – With conveying means to supply successive receivers – Sampler type
Reexamination Certificate
2000-07-07
2001-10-16
Jacyna, J. Casimer (Department: 3751)
Fluent material handling, with receiver or receiver coacting mea
With conveying means to supply successive receivers
Sampler type
C141S074000, C141S083000, C141S104000, C141S232000, C141S263000
Reexamination Certificate
active
06302168
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an automated precision liquid metering apparatus, and more particularly to an automated precision liquid metering apparatus which includes a plurality of injectors that are used as metering devices and can be controlled through a microcomputer and a control circuit to suck a fixed amount of specified liquid from a storage container and then be shifted to release the sucked liquid into a receptacle on an electronic balance at where the specified liquid is precisely measured.
2. Description of the Prior Art
Most of the currently commercially available automatic liquid metering apparatuses use metering valves to precisely control the amount of a specified liquid allowed to flow from a storage container to a receptacle.
FIG. 1
illustrates a most commonly adopted automatic liquid metering apparatus in which a plurality of storage containers
10
are included, a conveyance tube
11
is provided to extend between each storage container
10
and a receptacle
16
positioned on an electronic balance
15
, and a metering valve
12
is connected to the conveyance tube
11
at a point close to the storage container
10
. To use the above-described liquid metering apparatus to supply a precisely metered amount of a specified chemical liquid, a signal for opening the metering valve
12
that controls the flow of the specified liquid is sent by a control circuit
14
via a microcomputer
13
to the metering valve
12
. Under the siphonic action, the specified liquid flows from the storage container
10
via the conveyance tube
11
into the receptacle
16
on the electronic balance
15
. A signal representing a measured weight of the specified liquid in the receptacle
16
is then sent by the electronic balance
15
to the microcomputer
13
and the control circuit
14
. When the specified liquid reaches a predetermined amount, the microcomputer
13
and the control circuit
14
sends a signal to close the metering valve
12
and thereby stop the supply of the specified liquid from the storage container
10
. In a practical application of the above-described automatic precision liquid metering apparatus, as shown in
FIG. 2
, there are usually several decades or even several hundreds of storage containers
10
, conveyance tubes
11
and metering valves
12
included in the apparatus for the same to work economically and practically.
The following are some disadvantages of the above-described conventional precision liquid metering apparatus of FIG.
2
:
1. Each of the storage containers
10
must be equipped with one metering valve
12
to meter the amount of liquid flown out from the storage container
10
, and each metering valve
12
requires complicate wiring for forming its control circuit. The manufacturing cost of the whole precision liquid metering apparatus of
FIG. 2
is therefore very high.
2. In the event the metering valve
12
each includes a one-stage ON/OFF opening, such opening must be small for the metering valve
12
to precisely meter the liquid flowing therethrough. In this case, the flow rate of the liquid from the storage container
10
to the receptacle
16
is inevitably low and results in an extended time required to complete the supply of the specified liquid.
3. On the contrary, in the event the metering valve
12
each includes a multi-stage opening, although the specified liquid can be quickly supplied and precisely metered, the metering valve
12
would have more complicate structure and the apparatus of
FIG. 2
would therefore require higher manufacturing cost.
4. Each storage container
10
requires one conveyance tube
11
that also forms a considerable cost of the whole apparatus of FIG.
2
. And, it takes time for the specified liquid to flow from the storage container
10
via the conveyance tube
11
to the receptacle
16
. Moreover, chemicals in the specified liquid in the conveyance tube
11
tend to deposit because there is no way to stir the liquid and therefore well mix the chemicals in the conveyance tube
11
. Under this condition, even the liquid supplied to the receptacle is accurate in its total amount, it does not mean the chemicals in the liquid quantitatively meet specified amounts.
FIG. 3
illustrates another type of automatic precision liquid metering apparatus currently available in the market. In this second conventional precision liquid metering apparatus, the conveyance tubes
11
are omitted. The apparatus of
FIG. 3
mainly includes a central shaft
20
that horizontally extends through a rotary table
21
to bring the latter to rotate clockwise or counterclockwise. A plurality of storage containers
22
are mounted along an outer periphery of the rotary table
21
. Each storage container
22
is sealed with a cap
23
. On each cap
23
there is provided a passage
24
via which liquid flows out from the storage container
22
and an amount of compressed air is supplied into the storage container
22
, and a first solenoid valve
25
for controlling the open or close of the passage
24
. Insulated connectors extended from positive and negative electrodes of the first solenoid valve
25
are adapted to contact with external positive and negative electrodes to make the first solenoid valve
25
. The apparatus of
FIG. 3
is also controlled through a microcomputer
26
and a control circuit
27
that sends instructions about the types and amounts of liquid to be supplied from the storage containers
22
. When an instruction is sent, the rotary table
21
rotates to bring a storage container
22
having the specified liquid stored therein, that is referred to hereinafter as the selected storage container, to a topmost position on the rotary table
21
, so that the cap
23
of the selected storage container
22
faces straight upward for the passage
24
thereof to pivotally connect to an air outlet
28
of an air supply tube
29
. A second solenoid valve
34
is used to control the supply of air into the selected storage container
22
via the air supply tube
29
. Thereafter, the selected storage container
22
is brought by the rotary table
21
to a lowest position on the rotary table
21
, so that the cap
23
of the selected storage container
22
and the passage
24
thereof face straight downward. An electronic balance
30
carried on a traveling cart
31
is adapted to locate below the rotary table
21
. The traveling cart
31
is provided with positive and negative electrodes
32
that are adapted to electrically connect to the positive and the negative electrode connectors of the first solenoid valve
25
on the cap
23
of the selected storage container
22
, so that the passage
24
on the same cap
23
is opened by the first solenoid valve
25
thereof to allow liquid in the selected storage container
22
to flow into the receptacle
33
on the electronic balance
30
. The electronic balance
30
is able to feed back a signal representing the measured weight of the liquid in the receptacle
33
to the control circuit
27
and the microcomputer
26
. When the liquid in the receptacle
33
reaches a predetermined amount, the first solenoid valve
25
is shut off and the supply of liquid from the selected storage container
22
into the receptacle
33
is stopped. As in the first conventional precision liquid metering apparatus of
FIG. 2
, the apparatus of
FIG. 3
must include several decades or even several hundreds of storage containers
22
and each of which requires a solenoid valve
25
.
The following are some disadvantages of the second conventional precision liquid metering apparatus of
FIG. 3
without the conveyance tubes
11
:
1. The first solenoid valves
25
have limited usable life that is further shortened by frequent open and close of the first solenoid valves
25
.
2. Each storage container
22
has only one passage
24
and it is necessary to supply compressed air into the storage container
22
for an internal pressure thereof to be larger than an external atmospheric pressure to let the liquid out of the storage contai
deVore Peter
Jacyna J. Casimer
LandOfFree
Automated precision liquid metering apparatus using... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Automated precision liquid metering apparatus using..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Automated precision liquid metering apparatus using... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2601936