Weighing scales – Computer – Electrical
Reexamination Certificate
2000-05-19
2001-09-18
Gibson, Randy W. (Department: 2859)
Weighing scales
Computer
Electrical
C177S121000, C177S122000, C177S185000, C177SDIG009, C222S077000
Reexamination Certificate
active
06291781
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a combination weighing and counting apparatus and, more particularly, to a drive apparatus for at least one vibrating feeder used in the combination weighing and counting apparatus.
2. Description of the Prior Art
A combination weighing and counting apparatus utilizing vibrating feeders is shown in a schematic side sectional representation in FIG.
1
. The illustrated combination weighing and counting apparatus is supported on a machine base frame BF, and articles M transported by means of a supply conveyor
22
are supplied onto a center portion of a dispensing feeder
25
of a vibrating type through a supply chute
24
. A number N of vibrating feeders
1
(
1
-
1
to
1
-n) are radially disposed around and in the vicinity of an outer periphery of the dispensing feeder
25
and are so mounted on a frame F, which is in turn supported by the machine base frame BF, as to receive articles M dispensed radially outwardly from the dispensing feeder
25
while the latter is vibrated. The vibrating feeders
1
when vibrated at a predetermined amplitude and a predetermined frequency cause the articles M, received thereby, to move radially outwardly and then fall downwardly onto corresponding pool hoppers
26
(
26
-
1
to
26
-n) that are arranged in a circular row on the frame F at respective locations immediately below radially outer ends of the vibrating feeders
1
.
The articles M transported by means of the vibrating feeders
1
are, after having been temporarily pooled in the pool hoppers
26
(
26
-
1
to
26
-n) and after discharge gates
27
(
27
-
1
to
27
-n) of some of the pool hoppers
26
(
26
-
1
to
26
-n) that have been selected according to a weighing operation has been subsequently opened, supplied onto weighing hoppers
28
(
28
-
1
to
28
-n) that are also mounted on the frame F at respective locations immediately below and in alignment with the pool hoppers
26
(
26
-
1
to
26
-n). The weight of the articles M within each of the weighing hoppers
28
is measured by a corresponding weight detecting means
30
(
30
-
1
to
30
-n) such as a load cell from which a weight detection signal can be outputted. Based on this weight detection signal, a combination calculation is performed by a combination selecting means
20
built in a control device
31
, and some of the weighing hoppers
28
which result in the total weight of the articles M in those weighing hoppers
28
that falls within a tolerance range determined based on a target weight are selected, followed by opening of respective discharge gate
29
(
29
-
1
to
29
-n) of the selected weighing hoppers
28
with the articles M consequently collected onto associated collecting chutes
32
. The articles M so collected in the collecting chutes
32
are then discharged through a timing hopper
33
. The articles M discharged from the timing hopper
33
are packaged by a bagging machine
34
in a bag containing the articles M of a total weight equal to or substantially equal to the target weight.
The weighing hoppers
28
that have been emptied as a result of the previously described weighing operation perform the subsequent cycle of weighing operation after the articles have been supplied from the pool hoppers
26
during the subsequent weighing subsequent, and the vibrating feeders
1
that have supplied the articles onto the emptied pool hoppers
26
are simultaneously driven. After a predetermined quantity of articles have been supplied onto the pool hoppers
26
, the associated vibrating feeders
1
terminate their delivery operation and are held at a stand-by state. The foregoing operation of the combination weighing apparatus is executed under the control of the control device
31
.
Each of the vibrating feeders
1
comprises a vibrating mechanism including an electromagnet powered by an alternating current source, a movable body and leaf springs, and a trough adapted to be vibrated by the vibrating mechanism, wherein the length of time during which an electric power is supplied from the alternating current source to the electromagnet through a switching element comprised of a solid state relay (SSR) is adjusted by controlling the firing angle of the switching element and the articles on the trough are transported by vibrating the trough somewhat diagonally upwardly by the effect of a magnetic force of attraction, developed by the electromagnet, and a force of restoration developed by the leaf springs that are released from the magnetic force of attraction.
As hereinabove discussed, the plural vibrating feeders
1
are disposed radially around the dispensing feeder
25
and are so constructed that some of the vibrating feeders
1
associated with the plural emptied pool hoppers
26
can simultaneously perform transport operations. Since the prior art method of driving the vibrating feeders
1
is such that the plural vibrating feeders
1
can be driven simultaneously and in phase synchronized fashion to each other, the frame F to which the vibrating feeders
1
are mounted undergoes a considerable vibration in a vertical direction, that is, up and down vibration. This up and down vibration of the frame F adversely affects the weight detecting means that is also mounted on the same frame F, resulting in reduction of the weighing accuracy.
SUMMARY OF THE INVENTION
The present invention has been devised to substantially eliminate the above discussed problem and is intended to provide an improved combination weighing and counting apparatus wherein even though the plural vibrating feeders perform transport operations simultaneously, up and down vibration of the frame in a vertical direction can advantageously be minimized to avoid an undesirable reduction in weighing accuracy.
In order to accomplish this object, the present invention in one aspect thereof provides a combination weighing and counting apparatus which comprises a plurality of vibrating feeders for transporting articles; a plurality of weighing hoppers each operable to measure a weight of the articles supplied from the corresponding vibrating feeder; a combination selecting means for combining weights or numbers of the articles supplied to the weighing hoppers and for selecting a combination of the articles which falls within a tolerance range; and a feeder drive control means for driving the neighboring vibrating feeders at a driving phase opposite to each other.
According to the above described structure, since the driving phases of the neighboring vibrating feeders are set to be opposite to each other, vibrations brought about by the neighboring vibrating feeders act to counteract the vibrations of the support frame and the up and down vibration of the support frame on which the vibrating feeders are mounted can be suppressed, accompanied by increase in weighing and counting accuracy.
The present invention according to another aspect thereof also provides a combination weighing and counting apparatus which comprises a plurality of vibrating feeders for transporting articles; a plurality of weighing hoppers each operable to measure a weight of the articles supplied from the corresponding vibrating feeder; a combination selecting means for combining weights or numbers of the articles supplied to the weighing hoppers and for selecting a combination of the articles which falls within a tolerance range; and a feeder drive control means for driving substantially half of the vibrating feeders at a driving phase opposite to the remaining vibrating feeders. The combination selecting means referred to above is operable to select the combination of the weighing hoppers so that the driving phases of the vibrating feeders that supply the articles to the weighing hoppers which have been selected to discharge the articles are brought into a result of the driving phases of some of the vibrating feeders being opposite to those of the remaining vibrating feeders.
According to the above described structure, since a combination of the weighing hoppers is so selected that the dr
Kono Katsuaki
Ohtani Takafumi
Gibson Randy W.
Ishida Co. Ltd.
Staas & Halsey , LLP
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