U.S. patent application number 09/378914 was filed with the patent office on 2001-12-20 for extended range feeders.
Invention is credited to STEELE, JAMES R..
Application Number | 20010052430 09/378914 |
Document ID | / |
Family ID | 23495058 |
Filed Date | 2001-12-20 |
United States Patent
Application |
20010052430 |
Kind Code |
A1 |
STEELE, JAMES R. |
December 20, 2001 |
EXTENDED RANGE FEEDERS
Abstract
An attachment for a feeder conveyor with the attachment
comprising an angularly postionable gate that is angularly
postionable within the trough of a feeder with the postionable gate
having a secondary metering outlet so that when the postionable
gate is in the down position it partially close off the material
flow path within the feeder while allowing only a portion of the
solid materials in the material flow path to pass therethrough to
thereby extend the range at which material can be controllable and
uniformly delivered from the feeder.
Inventors: |
STEELE, JAMES R.;
(STILLWATER, MN) |
Correspondence
Address: |
CARL L JOHNSON
JACOBSON AND JOHNSON
ONE WEST WATER STREET SUITE 285
ST PAUL
MN
551072080
|
Family ID: |
23495058 |
Appl. No.: |
09/378914 |
Filed: |
August 23, 1999 |
Current U.S.
Class: |
177/108 ;
177/119; 222/547; 251/301 |
Current CPC
Class: |
B65G 27/00 20130101;
G01G 13/02 20130101 |
Class at
Publication: |
177/108 ;
177/119; 222/547; 251/301 |
International
Class: |
G01G 013/18; G01G
013/16; G01G 013/02; F16K 001/16; B67D 003/00; B65D 047/00 |
Claims
I claim:
1. A feeder for delivering material; a housing, said housing have
an inlet and an outlet; a trough located in said housing with said
trough extending between said inlet and said outlet and defining a
material path therethrough; a source of energy for powering said
feeder to enable material delivered to the inlet to be directed
from said outlet; and a gate, said gate mounted in said housing,
said gate postionable within said trough to control the size of the
material path therethrough to thereby control the amount of
material delivered from said feeder.
2. The feeder of claim 1 wherein the feeder comprises a vibratory
feeder.
3. The feeder of claim 1 wherein the gate is pivotally mounted for
positioning in the material flow path.
4. The feeder of claim 1 wherein the feeder comprises an
air-activated gravity feeder.
5. The feeder of claim 1 wherein the gate comprises an
angularly-postionable gate including a secondary outlet located in
a bottom section of the angularly-postionable gate.
6. The feeder of claim 4 wherein the feeder includes multiple
plenum chambers for fluidizing material therein.
7. The feeder of claim 6 wherein only one of the multiple plenum
chambers is used for fluidizing solid material thereon.
8. The feeder of claim 1 wherein a two way power cylinder connects
to said gate to thereby position said gate in the material flow
path therein to at least partially block off the material flow path
therein.
9. The feeder of claim 8 including a control module for controlling
the two way power cylinder.
10. The feeder of claim 9 including a base for vibratingly
supporting said trough thereon.
11. The feeder of claim 10 including a weigh scale for weighing the
material deliver thereto.
12. A method of reducing the rate of solid material delivery while
maintaining uniform delivery rates comprising: directing solid
materials into an inlet in a trough; directing solid materials
along a material flow path in the trough; moving a postionable gate
having a secondary outlet into the material flow path to reduce the
size of the flow path therein to thereby reduce the rate of solid
materials deliverable at a uniform rate.
13. The method of claim 12 including the step of positioning the
postionable gate at an acute angle with respect to the trough.
14. The method of claim 13 including the step of pivoting the
positionable gate into position to reduce the size of flow
path.
15. The method of claim 14 including the step of vibrating the
trough to direct the particles along the flow path.
16. The method of claim 12 including the step of directing air
through one of a plurality of plenum chambers to further decrease
the flow path.
17. The method of claim 16 including the step of varying the
pressure of air through the one of the plurality of plenum chambers
to further control the delivery of materials therefrom.
18. The method of claim 16 including the step of varying the volume
of air through the one of the plurality of plenum chambers to
further control the delivery of materials therefrom.
19. The method of claim 16 including the step of varying the number
of plenum chambers that air is supplied therein to further control
the delivery of materials therefrom.
20. A feeder for delivering material; a housing, said housing have
an inlet and an outlet; a trough located in said housing with said
trough extending between said inlet and said outlet and defining a
material path therethrough; a plurality of chambers in said
housing; a source of energy for delivering air under pressure to at
least one of the plurality of chambers to control the material
delivery rate; and a gate, said gate mounted in said housing, said
gate postionable within said trough to control the size of the
material path therethrough to thereby control the rate of material
delivered from said feeder.
21. The feeder of claim 20 including a member for increasing or
decreasing the air under pressure to further control the rate of
material delivery from said feeder.
22. The feeder of claim 20 including a further member for
increasing or decreasing the pressure of the air to further control
the rate of material from said feeder.
23. The feeder of claim 20 including having the plurality of
chambers of different size to further control the rate of material
delivery by selecting the size of the plenum chamber.
Description
FIELD OF THE INVENTION
[0001] This invention relaters generally to material delivery
systems and more particularly to a material delivery system for
delivering solid materials such as particles, granules or powders
over an extended range of material delivery rates.
BACKGROUND OF THE INVENTION
[0002] The concept of feeders such as vibratory feeders and gravity
feeders are known in the art. In the vibratory feeder, solid
material is fed into one end of a horizontal vibrating trough and
discharges from the other end as the vibrating action drives the
material from one end of the horizontal trough to the other end
where the material is discharged. By controlling the amount of
vibration applied to the trough and the amount of material
delivered to the trough the rate of material fed from the trough
can be controlled. Similarly, in an air-activated gravity feeder,
where the trough or chute is located at an angle, the solid
material flows from the upper end of a chute to the lower end of a
chute as air is blown upward through the solid material to fluidize
the material. By control of the amount of air supplied to the
air-activated gravity feeder and the amount of material delivered
to the air-activated gravity feeder the rate of material delivered
from the air-activated gravity feeder can be controlled. Both such
type of feeders are useful in the handling and delivering of solid
materials in measurable rates from one location to another. One of
the drawbacks of such systems is that the range of the rate of
material delivery for a particular feeder is limited. Typically,
prior art feeders can have a "turndown range" of about eight to
one. By "turndown range" it is understood to mean the ratio of the
maximum amount of material a feeder can deliver at a controlled or
uniform rate in relation the minimum amount of material a feeder
can deliver at a controlled or uniform rate. For example, with a
turndown range of eight to one the maximum amount the system can
deliver at a controlled or uniform rate is eight units per minute
and the minimum amount of material that the feeder can deliver at a
controlled or uniform rate is one unit per minute. While the
"turndown range" varies from machine to machine and from material
to material a characteristic of such feeders is that the range of
the rate of delivery of materials that can be fed is limited as one
cannot uniformly throttle down the rate of delivery of solid
particles like one can throttle down the flow of fluid with a
metering valve. This makes it difficult to use vibratory feeders or
air-activated gravity feeders for ladling out materials to weigh
scales as uneven flow can cause to much material to be delivered.
Consequently, to handle different flow rates at uniform type flow
rates multiple feeders having different capacity are often used in
the same system in order to obtain the necessary range of rate of
delivery of material. The present invention provides an attachment
that can increase the "turndown range" from eight to one to one
thousand to one while maintaining a substantially uniform material
delivery rate. As a result one size feeder can be used in a variety
of different applications.
DESCRIPTION OF THE PRIOR ART
[0003] U.S. Pat. No. 5,767,455 discloses a typical vibratory feeder
for delivering material from one location to another location.
[0004] Dynamic Air specification bulletin 9806 discloses an
air-activated gravity conveyor that can be built with various size
conveying chambers.
SUMMARY OF THE INVENTION
[0005] Briefly, the invention comprises an attachment for a
air-activated gravity or vibratory feeder with the attachment
comprising an angularly postionable gate that is angularly
postionable within the trough of a feeder with the postionable gate
having a secondary metering outlet so that when the postionable
gate is in the down position it partially close off the material
flow path within the feeder while allowing a portion of the solid
materials in the material flow path to pass therethrough to thereby
extend the range of rates at which material can be controllable and
uniformly delivered from the feeder.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 shows a partial sectional side view of a vibratory
feeder containing a postionable gate therein;
[0007] FIG. 2 is a partial sectional vie of a vibratory feeder with
the postionable gate in an out of the way condition so that
material can be directed through the vibratory feeder at the
maximum rate;
[0008] FIG. 3 shows a partial cross sectional view of the vibratory
feeder trough with the postionable gate located in the material
flow path;
[0009] FIG. 4 shows a side view of the vibratory feeder trough and
the postionable gate located at an angle .o slashed. within the
trough of the vibratory feeder of FIG. 1;
[0010] FIG. 5 is a cross sectional view of an air-activated gravity
conveyor for delving material from one location to another;
[0011] FIG. 6 is cross sectional view of the trough of the
air-activated gravity conveyor of FIG. 5 showing the porous screen
bed for directing material thereover;
[0012] FIG. 7 is a cross sectional view of the trough of the
air-activated gravity convey of FIG. 6 with multiple air plenum
chambers positioned below the porous screen bed;
[0013] FIG. 8 is a cross sectional view of the trough of the
air-activated gravity conveyor of FIG. 5 with a postionable gate
located in the material flow path in the air-activated
conveyor;
[0014] FIG. 9 is a cross of the trough of FIG. 5 with the
postionable gate located in an open condition to allow flow of
material within the material flow path of the air-activated
conveyor.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0015] FIG. 1 shows a partial sectional side view of a vibratory
feeder 10 containing an angularly postionable gate 11 therein.
Vibratory feeder includes a base 12 and a housing 13 having a
horizontal trough 13a supported by a set of spring plates 14. A
control module controls a vibrator drive motor 16 that has one end
mounted in base 12 and the other end attached to housing 13. The
trough 13a in vibratory feeder comprise a box-like channel with a
closed top 13b. Located on one end of trough 13a is an inlet 19 for
directing material into trough 13a. Located on the opposite end of
trough 13a is an outlet 20 for directing material therefrom. A
weigh scale 70 is located below outlet 20 and is connected to
control module 15 through lead 71.
[0016] Trough 13a includes a material flow path 21 that extends
from inlet 19 to outlet 20. In the embodiment shown the postionable
gate 11 of the present invention is shown extending into the
material flow path 21 to restrict the amount of material flowing
through the feeder. Postionable gate 11 is pivotable postionable
through a link 25 and a two way power cylinder 26. Power cylinder
is controlled by a lead 27 that extends from power cylinder 26 to a
control module 15.
[0017] In operation of the vibratory feeder of FIG. 1 the motor 16
vibrates the housing 13 thereby causing the material 30 in the
horizontal trough 13a to move from the inlet to the outlet through
the vibrator action imparted to the trough 13a. In the present
invention an angularly-postionable gate 11 has been mounted in
trough 13a with the angularly-postionable gate extending into the
material flow path 21 within the trough 13a to thereby restrict the
amount of solid material 30 flowing into outlet 20. Normally,
vibratory feeder 10 includes an unimpeded material flow path 21
therein so that the vibratory action on trough 13a can deliver
solid material from the inlet 19 to the outlet 20 by the vibratory
action of the material 30 thereon. That is the inertia of the
material 30 and the vibratory action of the trough 13a coact such
that the trough 13a moves back and forth while the material 30
moves from one end to another along the horizontally positioned
trough 13a.
[0018] In contrast, to the throttled down operation of the
vibratory feeder shown in FIG. 1, FIG. 2 is a partial sectional
view of a vibratory feeder 10 with the angularly-postionable gate
11 in an out of the way condition so that material can be directed
through the vibratory feeder at the maximum rate.
[0019] To illustrate the angularly-postionable gate 11 in relation
to the trough 13a and the material flow path reference should be
made to FIG. 3 which shows a partial cross sectional view of the
vibratory feeder trough 13a with the positionable gate 11 located
in the material flow path with a secondary metered gate outlet 11a
formed in the bottom portion of angularly-postionable gate 11.
[0020] FIG. 4 shows a side view of the vibratory feeder trough and
the angularly-postionable gate 11 located at an angle .o slashed.
within the trough of the vibratory feeder of FIG. 1.
Angularly-postionable gate comprises a flat plate having a lower
edge 11b that can be brought into engagement with the bottom of
trough 13a. Angularly-postionable gate 11 has sides 11c and lid
that cooperate with the sides of trough 13a to form an obstruction
to flow of material along material flow path 21. FIG. 4 shows that
the upper end 11e of angularly-postionable gate 11 is pivotally
supported by pivot hinge 30 which is pivotable through link 25.
[0021] As can be seen in FIG. 3 the positionable gate 11
substantially closes off the material flow path 21 with the
exception of the secondary metered outlet 11a formed in
angularly-positionable gate 11. The outlet 11a is shown as being
substantially rectangular however other shapes of outlets could be
used. The outlet 11a is also located along the bottom portion of
gate 11 so that the bottom of the trough 13a can continue to
support and form the delivery mechanism for delivering solid
material to outlet 20. Even though the materials 30 being delivered
by the vibratory feeder 10 are solid materials such as powders,
particles, or granular materials which do not readily flow from one
location to another is has been found that the partially closing
off of the material flow path by positioning a gate with a
secondary outlet therein allows material to be controllable
delivered at a substantially reduced and uniform rate from the
vibratory feeder. Consequently, the "turndown range" of the feeder
conveyor can be greatly extended. By being able to extend the
turndown range a single feeder conveyor can be used to deliver
material at a wide range of delivery rates. That is, the material
can be delivered at a controlled and uniform rate whether the
material flow path is unimpeded or partially closed off. FIG. 1
illustrates that a buildup of material 30 occurs immediately behind
angularly-postionable gate 11 but in spite of the buildup the
vibratory action of the vibratory feeder causes a diminished amount
of material 30 to be delivered in a uniform band through outlet 20.
FIG. 4 indicates by arrow that the angularly postionable gate 11
can be swung from an acute angle .o slashed. to the out of the way
position as shown in FIG. 2. In the preferred embodiment the angle
.o slashed. of the angularly-postionable gate .o slashed. is
maintained at 90.degree. or less and preferably at about 45.degree.
or less as it has been found that with many materials the material
will not clump but flow uniformly through the secondary outlet in
the angularly-postionable gate when the postionable gate is
angularly positioned with respect to the bottom of the trough 13a.
It should be understood that, the optimum angle .o slashed. of the
angularly-postionable gate can be determined by the type of solid
materials being handled in the feeder system. With some solid
materials the angle of the positionable gate may have to be small
and in others it may have to be large to prevent clumping and
uneven delivery of materials therethrough. The determination of the
optimum angle of the angularly-postionable gate for delivery of
controlled flow can readily determined by trial and error for a
particular solid material by merely observing at which angle the
feeder delivers a more uniform band of material 30 therefrom.
[0022] With the vibratory feeder 10 of FIG. 1, the rate of material
delivered can by decreased by placement of a postionable gate with
a secondary outlet in the vibratory feeder. Thus by having
different size secondary outlets one can limit the maximum delivery
rates. In addition even though the maximum delivery rate is limited
by the secondary outlet one can still maintain the proportional
control of the delivery rates by controlling the volume of material
supplied to the inlet of the vibratory feeder. Further proportional
control of the delivery rates can be obtained by controlling the
vibratory input to the vibratory feeder. Thus with the present
invention the ability to proportionally control the delivery rates
of the vibratory feeders is maintained even though the maximum rate
of material delivered is limited by use of the postionable gate
with the secondary outlet.
[0023] FIG. 5 is a cross sectional view of a gas-activated gravity
conveyor 40 for delivering material from one elevation to another
elevation. Gas-activated gravity conveyor 40 is normally supplied
with air and is referred to as an air-activated gravity conveyor 40
and includes a trough or chute 41 having an inlet 46 and an outlet
47. Located in the bottom of trough 41 is an air inlet 51 for
directing air or gas into a plenum chamber 43 which is separated
from an upper material flow path 52 by a porous screen 42. In
operation of air-activated gravity conveyor 40 material is directed
into inlet 46 when if flows onto porous screen 42 where the air
from plenum chamber 43 passes therethrough and fluidized material
50 so that the solid particle material can be delivered from the
inlet to the outlet.
[0024] FIG. 6 is a top sectional view taken along lines 6-6 which
shows the porous screen 42 mounted in trough 41 with a single
plenum chamber 43 located below porous screen 42.
[0025] FIG. 7 is a cross sectional view of the trough 41 of the
air-activated gravity conveyer of FIG. 6 with the trough 41
including multiple parallel air plenum chambers 43a, 43b and 43c
positioned along the bottom of trough 41. The use of multiple air
plenum chambers allows one to select a smaller fluidized bed. That
is, by pressurizing only air plenum chamber 43b the material in the
trough that is on top of the portion of screen 42 which is
proximate chamber 43b will be fluidized. Similarly, by pressurizing
two of the three air plenum chambers a larger fluidized bed can be
provided to thereby deliver solid materials at a faster rate. Thus
the use of multiple plenum chambers provides a further control of
the rate of material delivery by the gravity feeder.
[0026] FIG. 8 is a partial cross sectional view of the trough 41 of
the air-activated gravity conveyor 40 with an angularly-postionable
gate 61 pivotally mounted on a pivot hinge 62. The
angularly-postionable gate 61 is shown in the down position so that
material 50 can flow along material flow path 52 and tough a
secondary metering outlet (not shown) located in the bottom portion
of angularly-postionable gate 11. As the secondary metered outlet
of gate 61 is identical to the secondary metered outlet 11a of gate
11 it will not be described herein. With angularly-postionable gate
61 located in the material flow path in the air-activated conveyor
the rate of solid material flowing trough conveyor 40 can be
substantially reduced thereby allowing material to be delivered at
very low flow rates. In addition the use of multiple gas or air
plenum chambers allows one to both reduce the amount of fluidizing
material as well as to controllable and uniformly deliver a
controlled amount of material.
[0027] FIG. 9 is a partial cross sectional view of the trough of
the air-activated gravity conveyor 40 with a angularly-postionable
gate 61 pivotally mounted on pivot hinge 62. The
angularly-postionable gate 61 is shown in the out-of-the way
position so that material 50 can flow unimpeded along material flow
path 52. Thus with the present invention it is possible to
uniformly control the rate of delivery of solid materials at the
desired rate by placing an angularly-postionable gate with a
secondary outlet gate in the material feeder path. Consequently,
those applications where either large amounts of solid materials or
small amounts of solid material must be weighed out quickly can be
achieved with a single embodiment of present invention as the rates
of flow of materials therethrough can be controlled in a uniform
manner.
[0028] The angularly postionable gate of the present invention not
only provides for uniform delivery solid materials therethrough but
if the materials should accidentally clump up and block the opening
the postionable gate can be quickly swung out of the way to allow
the clump to pass through. Once the clump has passed through the
postionable gate can be quickly swung into the metering
position.
[0029] With the feeder 40 of FIG. 5, the rate of material delivery
can by decreased by placement of a postionable gate with a
secondary outlet in the gravity feeder. Thus by having different
size secondary outlets one can limit the maximum delivery rates. In
addition, further control of the delivery rates can be obtained by
decreasing the size, number or shape of the plenum chambers. For
example, a single plenum chamber such as chamber 43b can be used to
fluidize the material which would limit the amount of material that
could flow down the gravity feeder. Even though the maximum
delivery rates are limited by the secondary outlet of the present
invention, one can still maintain the proportional control of the
delivery rates by controlling the volume of material supplied to
the inlet of the gravity feeder. Further proportional control of
the delivery rates can be obtained by controlling the pressure of
the air supplied to the gravity feeder. Thus with the present
invention the ability to proportionally control the delivery rates
of the gravity feeders is maintained even though the rate of
material delivery is limited by use of the postionable gate with
the secondary outlet.
[0030] Thus with the present invention a member such as an air
source for increasing or decreasing the air under pressure to
further control the rate of material delivery from said feeder. In
addition the present invention including a further member such as a
valve for increasing or decreasing the pressure of the air to
further control the rate of material from said feeder. As a further
control of the material delivery rate the present can include a
plurality of chambers of different size to further control the rate
of material delivery by selecting the size of the plenum
chamber.
* * * * *