Information
-
Patent Grant
-
6425804
-
Patent Number
6,425,804
-
Date Filed
Tuesday, March 21, 200024 years ago
-
Date Issued
Tuesday, July 30, 200222 years ago
-
Inventors
-
Original Assignees
-
Examiners
- Hail, III; Joseph J.
- Ojini; Anthony
-
CPC
-
US Classifications
Field of Search
US
- 451 38
- 451 75
- 451 89
- 451 99
-
International Classifications
-
Abstract
A pressurized delivery system for abrasive particulate material includes a storage container adapted to contain the abrasive particulate material therein, an input pressure line adapted to communicate with a pressurized source, and a fluidizing pressure line communicating with the input pressure line and an inlet opening in the storage container. A back-pressure pressure line communicates with an unoccupied portion of the storage container and an output pressure line. The output pressure line, into which the abrasive particulate material is fed from the storage container, communicates with the input pressure line, the back-pressure pressure line, and an outlet opening of storage container. During operation, pressurized gas is released through the inlet opening and into the storage container such that the abrasive particulate material adjacent the outlet opening is fluidized and maintained flowable so as to achieve consistent flow of the abrasive particulate material through the outlet opening.
Description
THE FIELD OF THE INVENTION
The present invention relates generally to a system for delivering abrasive particulate material under pressure, and more particularly to a system which utilizes a pressurized source to fluidize and deliver abrasive particulate material for abrading a surface of another material, such as for abrading a portion of a silicon substrate of an ink-jet printhead to thereby form an ink fill slot in the silicon substrate.
BACKGROUND OF THE INVENTION
A conventional process, commonly referred to as sandblasting, combines abrasive particulate material, such as sand, with a pressurized source of gas, for example, air, to form an abrasive mixture under pressure and directs the abrasive mixture under pressure at a surface. Such a conventional sandblasting process is typically used for cleaning, polishing, or abrading the surface at which the abrasive mixture is directed. Existing sandblasting systems typically include a storage container adapted to contain the abrasive particulate material therein, and a pressure line through which the pressurized source of gas is directed and into which the abrasive particulate material is fed by gravity flow from the storage container.
More particularly, sandblasting has been employed to form an ink fill slot in a silicon substrate of an ink-jet printhead. Existing sandblasting systems employed for forming the ink fill slot typically rely on gravity flow, vibration of the storage container, and/or modulation of the pressure line to ensure discharge of the abrasive particulate material from the storage container, through a metering orifice, and into the pressure line. The vibration and/or modulation in these existing sandblasting systems, however, results in chaotic behavior, or inconsistent flow, of the abrasive particulate material through the metering orifice. This chaotic behavior resulting when the ink fill slot is formed with existing sandblasting systems is identified by random size and shape variations of the ink fill slot. Since the ink fill slot provides a supply of ink to a printing element of the ink-jet printhead during a printing process, a distance from the ink fill slot to the printing element effects the supply of ink to the printing element. Size and shape variations in the ink fill slot, therefore, can degrade printing performance.
Accordingly, a need exists for a system for delivering abrasive particulate material under pressure which provides consistent flow of the abrasive particulate material from a storage container, through a metering orifice, and into an output pressure line. In particular, there is a need for a method for more uniformly forming an ink fill slot in a silicon substrate of an ink-jet printhead.
SUMMARY OF THE INVENTION
One aspect of the present invention provides a pressurized delivery system for abrasive particulate material. The pressurized delivery system includes a storage container adapted to contain the abrasive particulate material therein, an inlet valve communicating with an inlet opening of the storage container, and a first flow path communicating with the inlet valve. A second flow path, adapted to communicate with a pressurized source of gas, communicates with the first flow path, and a third flow path communicates with the second flow path in parallel flow with the first flow path. A fourth flow path communicates with an unoccupied portion of an interior space of the storage container, and a fifth flow path communicates with the third flow path, an outlet opening of the storage container, and the fourth flow path. As such, a pressurized supply of the abrasive particulate material may be formed and delivered through the fifth flow path.
In one embodiment, the third flow path is in parallel flow with the first flow path from the second flow path.
In one embodiment, the abrasive particulate material includes sand, aluminum oxide, silicon carbide, quartz, or diamond dust. In one embodiment, the gas is air and in another embodiment, the gas is an inert gas for use, for example, when a material to be processed with the pressurized delivery system is sensitive to air and oxidation of the material is a concern.
In one embodiment, the inlet valve is a one-way valve and in one embodiment, the one-way valve is a duckbill check valve which is effective at creating a tight seal when closed despite communicating with the abrasive particulate material.
In one embodiment, an adjustable control valve is provided in-line in the first flow path before the inlet valve to set a desired flow rate of pressurized gas supplied to the inlet valve. In one embodiment, a first check valve is provided in-line in the second flow path before the first flow path and the third flow path, and a second check valve is provided in-line in the third flow path. In one embodiment, a filter is provided in-line in the third flow path after the second check valve to help keep the abrasive particulate material from back streaming into the second check valve.
In one embodiment, the fourth flow path includes an inlet orifice communicating with the unoccupied portion of the interior space of the storage container to restrict input to the fourth flow path.
In one embodiment, a baffle is positioned within the storage container above the inlet opening to disperse pressurized gas released into the interior space of the storage container so as to more evenly distribute pressurized air throughout a base of the storage container. In one embodiment, a nozzle is provided at an output end of the fifth flow path for accelerating and directing the abrasive particulate material toward a surface to be processed.
Another aspect of the present invention provides a pressurized delivery system for abrasive particulate material. The pressurized delivery system includes an input pressure line having a first end adapted to communicate with a pressurized source of gas, a fluidizing pressure line having a first end communicating with the input pressure line, and a storage container adapted to contain the abrasive particulate material therein. An inlet valve communicates with a second end of the fluidizing pressure line and an inlet opening of the storage container. A back-pressure pressure line has a first end communicating with an unoccupied portion of an interior space of the storage container, and an output pressure line has a first end communicating with a second end of the input pressure line, a second end of the back-pressure pressure line, and an outlet opening of the storage container. As such, a pressurized supply of the abrasive particulate material may be formed and delivered through the output pressure line.
Another aspect of the present invention provides a method of delivering abrasive particulate material under pressure from a storage container adapted to contain the abrasive particulate material therein. The method includes the steps of communicating an inlet valve with an inlet opening of the storage container and supplying a first gas, regulated to a first predetermined pressure, to the inlet valve. The first gas is released through the inlet valve and into the storage container, and a quantity of the abrasive particulate material is discharged through an outlet opening of the storage container to an output junction. In addition, a second gas, regulated to a second predetermined pressure, is supplied to the output junction. As such, a pressurized supply of the abrasive particulate material is formed and delivered through the output junction.
Another aspect of the present invention provides a method of abrading a portion of a silicon substrate. The method includes the steps of fluidizing abrasive particulate material with a first gas within a storage container, combining the gas fluidized abrasive particulate material with a stream of a second gas to provide a stream of the gas fluidized abrasive particulate material, and directing the stream of the gas fluidized abrasive particulate material at the silicon substrate to abrade the portion of the silicon substrate.
Another aspect of the present invention provides a method of forming an ink fill slot in a silicon substrate of an ink-jet printhead. The method includes the steps of fluidizing abrasive particulate material with a first gas within a storage container, combining the gas fluidized abrasive particulate material with a stream of a second gas to provide a stream of the gas fluidized abrasive particulate material, and directing the stream of the gas fluidized abrasive particulate material at the silicon substrate to form the ink fill slot in the silicon substrate.
Another aspect of the present invention provides an ink-jet printhead including a silicon substrate having an ink fill slot formed therein by fluidizing abrasive particulate material with a first gas within a storage container, combining the gas fluidized abrasive particulate material with a stream of a second gas to provide a stream of the gas fluidized abrasive particulate material, and directing the stream of the gas fluidized abrasive particulate material at the silicon substrate to form the ink fill slot in the silicon substrate.
The present invention provides a system for delivering abrasive particulate material under pressure such that more accurately metered flow of the abrasive particulate material from a storage container, through a metering orifice, and into an output pressure line is achieved. More particularly, the present invention provides a method for more uniformly forming an ink fill slot in a silicon substrate of an inkjet printhead.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1
is a schematic view of a pressurized delivery system for abrasive particulate material according to the present invention;
FIG. 2
is an enlarged view of a portion of
FIG. 1
illustrating portions of the pressurized delivery system including an inlet valve in an opened state;
FIG. 3
is an enlarged view of a portion of
FIG. 1
illustrating portions of the pressurized delivery system including an inlet valve in a closed state;
FIG. 4
is a perspective view of a portion of an ink-jet printhead including an ink fill slot formed in a silicon substrate by a pressurized delivery system according to the present invention;
FIG. 5
is a top view of a portion of an ink-jet printhead including a plurality of printing elements formed on a silicon substrate and an ink fill slot formed in the silicon substrate by a pressurized delivery system according to the present invention; and
FIG. 6
is a cross-sectional view of an ink fill slot formed in a silicon substrate by a pressurized delivery system according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the following detailed description of the preferred embodiments, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present invention. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims.
FIG. 1
illustrates one embodiment of a pressurized delivery system
10
for abrasive particulate material
12
according to the present invention. Pressurized delivery system
10
includes a storage container
20
, an input pressure line
30
, a fluidizing pressure line
40
, an inlet valve
50
, a back-pressure pressure line
60
, and an output pressure line
70
. Storage container
20
defines an interior space
22
adapted to contain abrasive particulate material
12
therein. When abrasive particulate material
12
is deposited within storage container
20
, an occupied portion
22
a
and unoccupied portion
22
b
of interior space
22
are defined. Unoccupied portion
22
b
includes a portion of interior space
22
devoid of abrasive particulate material
12
. Abrasive particulate material
12
may include sand, aluminum oxide, silicon carbide, quartz, diamond dust, or any other suitable abrasive material in particulate form or particulate material having suitable abrasive qualities for a desired application of pressurized delivery system
10
.
In one embodiment, storage container
20
is generally cylindrical in shape and includes a base
24
having an inlet opening
26
and an outlet opening
28
defined therein. Outlet opening
28
functions as a metering orifice through which abrasive particulate material
12
is fed to output pressure line
70
. In one embodiment, inlet opening
26
is adjacent to outlet opening
28
and a baffle
25
is provided above inlet opening
26
. In addition, base
24
of storage container
20
includes a bottom wall
24
a
, in which inlet opening
26
and outlet opening
28
are formed, and an inwardly, downwardly sloping side wall
24
b
. Inwardly, downwardly sloping side wall
24
b
facilitates gravity flow of abrasive particulate material
12
downward within storage container
20
toward outlet opening
28
.
Input pressure line
30
has a first end
32
and a second end
34
. First end
32
of input pressure line
30
is adapted to communicate with a pressurized source of gas
14
. Second end
34
of input pressure line
30
communicates with an output junction
76
of output pressure line
70
. In one embodiment, the gas is air delivered by a pressure regulating system
16
. In an alternate embodiment, the gas includes an inert gas, such as argon. Use of inert gas may be preferred, for example, when a material to be processed with pressurized delivery system
10
is sensitive to air and oxidation of the material is a concern. For clarity, the following description only refers to using pressurized air, but it is understood that use of other gases, or combinations of gases, is within the scope of the present invention.
In one embodiment, a series of check valves are provided in input pressure line
30
. The check valves include a low-pressure check valve
37
and a resister check valve
38
. In addition, a filter
39
is provided in-line in input pressure line
30
after resister check valve
38
. Filter
39
helps keep abrasive particulate material
12
from back streaming into resister check valve
38
. An example of such a filter is a 9071-20-⅛, 25 micron filter manufactured by Arrow.
Low-pressure check valve
37
is provided in-line in input pressure line
30
to prevent back flow from storage container
20
into pressure regulating system
16
if a pressure drop occurs. Low-pressure check valve
37
has a low cracking pressure, for example, ⅓ pounds per square inch (psi), to reduce overall pressure drop in the system. An example of such a check valve is a SS-6C-⅓ check valve manufactured by Nupro. Resister check valve
38
is provided in-line in input pressure line
30
after low-pressure check valve
37
. Resister check valve
38
produces a fairly constant pressure drop equal to its cracking pressure, for example, 10 psi. An example of such a check valve is a 4M-C4L-10-B check valve manufactured by Parker.
Resister check valve
38
develops a pressure in both input pressure line
30
, between low-pressure check valve
37
and resister check valve
38
, and fluidizing pressure line
40
which is higher than a pressure in input pressure line
30
after resister check valve
38
. As such, a higher regulated pressure is developed before resister check valve
38
and a lower regulated pressure is developed after resister check valve
38
. This higher pressure, before resister check valve
38
, produces a drive pressure for fluidizing pressure line
40
. A benefit of resister check valve
38
is that it automatically produces a fairly constant pressure drop regardless of output pressure settings. In an alternate embodiment, a first pressure regulator (not shown) is provided in-line in input pressure line
30
before fluidizing pressure line
40
and a second pressure regulator (not shown) is provided in-line in input pressure line
30
after fluidizing pressure line
40
. The first and second pressure regulators, however, must each be adjusted in response to output pressure setting changes to develop the desired pressure drop within input pressure line
30
for producing drive pressure for fluidizing pressure line
40
.
Fluidizing pressure line
40
has a first end
42
and a second end
44
. First end
42
of fluidizing pressure line
40
communicates with an input junction
36
provided in input pressure line
30
between low-pressure check valve
37
and resister check valve
38
. Second end
44
of fluidizing pressure line
40
communicates with inlet valve
50
. As such, fluidizing pressure line
40
provides a by-pass flow path which is in parallel flow with input pressure line
30
from input junction
36
. In one embodiment, a control valve
46
is provided in-line in fluidizing pressure line
40
before inlet valve
50
. Control valve
46
is an adjustable valve used to set a desired flow rate, referred to as a fluidizing flow rate, of pressurized air supplied to inlet valve
50
. An example of such a control valve is a MNV-1K needle valve manufactured by Clippard.
Inlet valve
50
communicates with fluidizing pressure line
40
on an input side
52
(
FIG. 2
) and inlet opening
26
of storage container
20
on an output side
54
(FIG.
2
). Inlet valve
50
has an opened state, illustrated in
FIG. 2
, and a closed state, illustrated in
FIG. 3
, depending on an operational state of pressurized delivery system
10
. Inlet valve
50
is a one-way valve that permits substantially no flow in an upstream direction while permitting flow only in a downstream direction from fluidizing pressure line
40
to storage container
20
. In one embodiment, inlet valve
50
is made of a flexible material, for example, rubber, and is commonly referred to as a flapper, or duckbill, check valve. The duckbill check valve is effective at creating a tight seal when closed despite communicating with abrasive particulate material
12
. An example of such a check valve is a VL1490-102 check valve manufactured by Vernay Laboratories.
In an alternate embodiment, inlet valve
50
is a porous material (not shown) that permits air to flow from fluidizing pressure line
40
to storage container
20
, but does not permit abrasive particulate material
12
to flow into fluidizing pressure line
40
. The porous material suitably includes natural stones, micro-screen, filter cloth, or similar performing material. An example of such a material is a macroporous material formed of nylon and having a mesh opening of 8 microns manufactured by Spectrum.
Back-pressure pressure line
60
has a first end
62
and a second end
64
. First end
62
of back-pressure pressure line
60
communicates with unoccupied portion
22
b
of interior space
22
of storage container
20
. Second end
64
of back-pressure pressure line
60
communicates with output junction
76
of output pressure line
70
. An inlet orifice
66
is provided at first end
62
of back-pressure pressure line
60
and has a diameter less than that of back-pressure pressure line
60
. As such, inlet orifice
66
restricts input of air into back-pressure pressure line
60
and reduces sensitivity of the system to differing levels of abrasive particulate material
12
contained within storage container
20
. It is theorized that back-pressure created by inlet orifice
66
increases a head on outlet opening
28
so that a head created by abrasive particulate material
12
itself is not the sole contributor to flow of abrasive particulate material
12
through outlet opening
28
. Thus, variation of flow caused by differing levels of abrasive particulate material
12
within storage container
20
is reduced.
Output pressure line
70
has a first end
72
and a second end
74
. First end
72
of output pressure line
70
communicates with second end
34
of input pressure line
30
, second end
64
of back-pressure pressure line
60
, and outlet opening
28
of storage container
20
at output junction
76
. An abrasive pinch
77
is provided in output pressure line
70
and a vent pinch
78
is provided in a vent tube
79
communicating with output pressure line
70
before abrasive pinch
77
. In addition, a nozzle
80
is provided at second end
74
of output pressure line
70
. Nozzle
80
accelerates and directs abrasive particulate material
12
toward a surface to be processed. Abrasive pinch
77
and vent pinch
78
are used during operation of pressurized delivery system
10
, as is known in the art.
In use, abrasive particulate material
12
is disposed within interior space
22
of storage container
20
to a level such that first end
64
of back-pressure pressure line
60
communicates with unoccupied portion
22
b
of interior space
22
. In one illustrative embodiment, abrasive particulate material
12
is aluminum oxide. Pressurized air
14
is regulated and supplied, by pressure regulating system
16
, to first end
32
of input pressure line
30
, and first end
42
of fluidizing pressure line
40
after passing through low-pressure check valve
37
. To operate pressurized delivery system
10
, abrasive pinch
77
is opened, as illustrated in FIG.
1
. Resister check valve
38
, however, remains closed until a predetermined pressure differential, for example, 10 psi, occurs across resister check valve
38
. This develops higher pressure before resister check valve
38
and produces drive pressure for fluidizing pressure line
40
. When the predetermined pressure differential does occur across resister check valve
38
, pressurized air
14
is released through resister check valve
38
and through filter
39
to output junction
76
.
During operation, control valve
46
is adjusted to establish a desired fluidizing flow rate of pressurized air
14
to inlet valve
50
. In one illustrative embodiment, with a standardized pressure of 4 psi, the fluidizing flow rate is adjusted to 6.0 standard cubic feet per hour (SCFH). The flow of pressurized air
14
causes inlet valve
50
to open, as illustrated in FIG.
2
. As such, pressurized air
14
, referred to as a fluidizing air stream, is released into interior space
22
of storage container
20
, through inlet opening
26
. Thereafter, baffle
25
disperses, or spreads out, pressurized air
14
released into interior space
22
of storage container
20
so as to more evenly distribute pressurized air
14
throughout base
24
of storage container
20
. Since outlet opening
28
is adjacent to inlet opening
26
, abrasive particulate material
12
adjacent outlet opening
28
is “fluidized.” Essentially, abrasive particulate material
12
adjacent outlet opening
28
develops a fluidic trait and, as such, is maintained flowable through outlet opening
28
. Thus, abrasive particulate material
12
is more accurately metered as it flows consistently through outlet opening
28
and to output junction
76
where it joins pressurized air
14
released through resister check valve
38
.
While abrasive particulate material
12
flows through outlet opening
28
, a portion of the fluidizing air stream released into storage container
20
by inlet valve
50
is released through outlet opening
28
and to output junction
76
with abrasive particulate material
12
. A portion of the fluidizing air stream released into storage container
20
by inlet valve
50
also permeates through abrasive particulate material
12
to unoccupied portion
22
b
of interior space
22
where it is vented through back-pressure pressure line
60
to output junction
76
. As such, abrasive particulate material
12
and the portion of the fluidizing air stream released through outlet opening
28
with abrasive particulate material
12
, pressurized air
14
released through resister check valve
38
, and the portion of the fluidizing air stream vented through back-pressure pressure line
60
, come together at output junction
76
to form a pressurized abrasive particulate material/air mixture
18
. As such, pressurized abrasive particulate material/air mixture
18
is supplied to output pressure line
70
. Thereafter, pressurized abrasive particulate material/air mixture
18
is accelerated through nozzle
80
.
To discontinue operation, or develop a stand-by state, of pressurized delivery system
10
, abrasive pinch
77
is closed. With abrasive pinch
77
closed, pressurized air
14
no longer flows through pressurized delivery system
10
. Inlet valve
50
, therefore, returns to the closed state, as illustrated in FIG.
3
. Thus, a static mode of pressurized delivery system
10
is established.
Referring to
FIGS. 4-6
, one illustrative application of pressurized delivery system
10
is for forming an ink fill slot
122
in a silicon substrate
120
of an ink-jet printhead
100
for an ink-jet printer (not shown).
FIG. 4
illustrates a portion of ink-jet printhead
100
including a printing, or drop ejecting, element
110
formed on substrate
120
. Ink fill slot
122
, formed in substrate
120
, provides a supply of ink (not shown) to a plurality of printing elements
110
as illustrated in FIG.
5
. Although
FIG. 5
illustrates one common configuration of a plurality of printing elements
110
including two parallel rows of printing elements
110
along ink fill slot
122
, other configurations of printing elements
110
employed in ink-jet printers, including approximately circular and single row configurations, are within the scope of the present invention.
As illustrated in
FIG. 4
, printing element
110
includes a layer
112
having an ink feed channel
113
formed therein, a resistor
116
positioned within ink feed channel
113
, and a nozzle plate
118
having a nozzle
119
formed therein. Ink feed channel
113
forms a drop ejection chamber
115
surrounding resistor
116
on three sides. Ink (not shown) is supplied from ink fill slot
122
to drop ejection chamber
115
through a pair of opposed projections
114
provided at an entrance to ink feed channel
113
. Nozzle
119
is operatively associated with resistor
116
such that droplets of ink are ejected through nozzle
119
(e.g., normal to the plane of resistor
116
) and toward a print medium (not shown) upon heating of a quantity of ink by resistor
116
. As such, alphanumeric characters and graphics are formed on the print medium (not shown).
As illustrated in
FIG. 6
, substrate
120
has a first surface
124
and a second surface
126
upon which printing element
110
is formed. Second surface
126
is opposed to and substantially parallel with first surface
124
. In one embodiment, substrate
120
comprises a single crystal silicon wafer, commonly used in the microelectronics industry. In addition, ink fill slot
122
communicates with both first surface
124
and second surface
126
, and converges from first surface
124
toward second surface
126
. As such, ink fill slot
122
provides a supply of ink (not shown) to second surface
126
and, therefore, printing element
110
.
In accordance with the present invention, pressurized delivery system
10
is used to form ink fill slot
122
in silicon substrate
120
by directing a stream of pressurized abrasive particulate material/air mixture
18
at first surface
124
of silicon substrate
120
. The stream of pressurized abrasive particulate material/air mixture
18
is directed at first surface
124
at least until ink fill slot
122
communicates with second surface
126
of silicon substrate
120
. Since ink fill slot
122
provides the supply of ink to printing element
110
during the printing process, printing performance depends on uniformity of ink fill slot
122
. A distance from an edge of ink fill slot
122
to drop ejection chamber
115
, for example, determines how rapidly drop ejection chamber
115
can refill with ink after ink is ejected from drop ejection chamber
115
during the printing process. How rapidly drop ejection chamber
115
can refill with ink, in turn, effects a frequency of operation of printing element
110
and, therefore, printing speed. Compared with existing sandblasting systems employed for forming ink fill slot
122
, pressurized delivery system
10
has been shown to significantly reduce size and shape variations of ink fill slot
122
.
While pressurized delivery system
10
has been described and illustrated for use in forming ink fill slot
122
in silicon substrate
120
of ink-jet printhead
100
with pressurized abrasive particulate material/air mixture
18
, it is apparent that pressurized delivery system
10
is useful for other cleaning, polishing, abrading or related operations. Other example embodiments of pressurized delivery system
10
are employed for removing paint, rust, or other foreign materials from surfaces including metal, concrete, or the like, cleaning or polishing jewelry or corroded articles, and/or abrading or polishing steel or other metal components.
Fluidizing pressure line
40
supplies pressurized air
14
to storage container
20
so as to fluidize a quantity of abrasive particulate material
12
contained therein. As such, abrasive particulate material
12
flows consistently through outlet opening
28
of storage container
20
to join pressurized air
14
supplied to output pressure line
70
. Pressurized delivery system
10
, therefore, provides a system for delivering abrasive particulate material under pressure such that more accurately metered flow of the abrasive particulate material from a storage container, through a metering orifice, and into an output pressure line is achieved.
Although specific embodiments have been illustrated and described herein for purposes of description of the preferred embodiment, it will be appreciated by those of ordinary skill in the art that a wide variety of alternate and/or equivalent implementations calculated to achieve the same purposes may be substituted for the specific embodiments shown and described without departing from the scope of the present invention. Those with skill in the chemical, mechanical, electro-mechanical, electrical, and computer arts will readily appreciate that the present invention may be implemented in a very wide variety of embodiments. This application is intended to cover any adaptations or variations of the preferred embodiments discussed herein. Therefore, it is manifestly intended that this invention be limited only by the claims and the equivalents thereof.
Claims
- 1. A pressurized delivery system for abrasive particulate material, the pressurized delivery system comprising:a storage container defining an interior space adapted to contain the abrasive particulate material therein, the storage container including a base having an inlet opening and an outlet opening defined therein; an inlet valve communicating with the inlet opening; a first flow path communicating with the inlet valve; a second flow path communicating with the first flow path and adapted to communicate with a pressurized source of gas; a third flow path communicating with the second flow path; a fourth flow path communicating with an unoccupied portion of the interior space of the storage container; and a fifth flow path communicating with the third flow path, the outlet opening, and the fourth flow path.
- 2. The pressurized delivery system of claim 1, wherein the third flow path is in parallel flow with the first flow path from the second flow path.
- 3. The pressurized delivery system of claim 1, wherein the abrasive particulate material includes at least one of sand, aluminum oxide, silicon carbide, quartz, and diamond dust.
- 4. The pressurized delivery system of claim 1, wherein the gas is air.
- 5. The pressurized delivery system of claim 1, wherein the gas is an inert gas.
- 6. The pressurized delivery system of claim 1, wherein the inlet valve is a one-way valve.
- 7. The pressurized delivery system of claim 6, wherein the one-way valve is a duckbill check valve.
- 8. The pressurized delivery system of claim 1, further comprising:an adjustable control valve provided in-line in the first flow path before the inlet valve.
- 9. The pressurized delivery system of claim 1, further comprising:a first check valve provided in-line in the second flow path before the first flow path and the third flow path; and a second check valve provided in-line in the third flow path.
- 10. The pressurized delivery system of claim 9, further comprising:a filter provided in-line in the third flow path after the second check valve.
- 11. The pressurized delivery system of claim 1, wherein the fourth flow path includes an inlet orifice communicating with the unoccupied portion of the interior space of the storage container, the inlet orifice restricting input to the fourth flow path.
- 12. The pressurized delivery system of claim 1, further comprising:a baffle positioned within the storage container above the inlet opening.
- 13. The pressurized delivery system of claim 1, further comprising:a nozzle provided at an output end of the fifth flow path.
- 14. A pressurized delivery system for abrasive particulate material, the pressurized delivery system comprising:an input pressure line having a first end and a second end, the first end adapted to communicate with a pressurized source of gas; a fluidizing pressure line having a first end and a second end, the first end of the fluidizing pressure line communicating with the input pressure line intermediate the first and second ends of the input pressure line; an inlet valve communicating with the second end of the fluidizing pressure line; a storage container defining an interior space adapted to contain the abrasive particulate material therein, the storage container including a base having an inlet opening and an outlet opening defined therein, the inlet opening communicating with the inlet valve; a back-pressure pressure line having a first end and a second end, the first end of the back-pressure pressure line communicating with an unoccupied portion of the interior space of the storage container; and an output pressure line having a first end and a second end, the first end of the output pressure line communicating with the second end of the input pressure line, the second end of the back-pressure pressure line, and the outlet opening of the storage container.
- 15. The pressurized delivery system of claim 14, wherein a portion of the input pressure line is in parallel flow with the fluidizing pressure line.
- 16. The pressurized delivery system of claim 14, wherein the abrasive particulate material includes at least one of sand, aluminum oxide, silicon carbide, quartz, and diamond dust.
- 17. The pressurized delivery system of claim 14, wherein the gas is air.
- 18. The pressurized delivery system of claim 14, wherein the gas is an inert gas.
- 19. The pressurized delivery system of claim 14, wherein the inlet valve is a one-way valve.
- 20. The pressurized delivery system of claim 19, wherein the one-way valve is a duckbill check valve.
- 21. The pressurized delivery system of claim 14, further comprising:an adjustable control valve provided in-line in the fluidizing pressure line before the inlet valve.
- 22. The pressurized delivery system of claim 14, further comprising:a first check valve provided in-line in the input pressure line before the fluidizing pressure line; and a second check valve provided in-line in the input pressure line after the fluidizing pressure line.
- 23. The pressurized delivery system of claim 22, further comprising:a filter provided in-line in the input pressure line after the second check valve.
- 24. The pressurized delivery system of claim 14, wherein the back-pressure pressure line includes an inlet orifice communicating with the unoccupied portion of the interior space of the storage container, the inlet orifice restricting input to the back-pressure pressure line.
- 25. The pressurized delivery system of claim 14, further comprising:a baffle positioned within the storage container above the inlet opening.
- 26. The pressurized delivery system of claim 14, further comprising:a nozzle provided at the second end of the output pressure line.
US Referenced Citations (12)