US3823302A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus and method for plasma spraying
Assignee: Geotel Inc
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Filing: 1973-06-21
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Granted: 1974-07-09
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Expires: 1993-06-21
Abstract
Abstract An extremely high-powered electrical plasma-jet spray torch is constructed economically, safely, and in a compact manner, by use of three coaxial body members held together by longitudinal, internal bolts. No external housing is necessary, the handle being screwed directly onto one of the body members. Two removable electrodes are provided and are separated from each other by a gas-injector ring of heat-resistant insulating material. The electrode ends adjacent the gas injector are watercooled and are provided with O-ring seals. Powder is injected into the plasma by use of a rotatable anode adapted to permit selective use of different types of injection, thus vastly increasing the utility of the anode. In accordance with the method, supersonic flow is employed in combination with very high powers, and plural-port powder injection, to achieve extremely high spray rates.
Inventors
- 👤 E Muehlberger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 10:28
CPC Classifications
B; B05; B05B; B05B7/00; B05B7/16; B05B7/168; B05B7/22; B05B7/222; B05B7/226; C; C23; C23C; C23C4/00; C23C4/12; C23C4/134; C23C4/137; H; H05; H05H; H05H1/00; H05H1/24; H05H1/26; H05H1/32; H05H1/42
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
328 words
A high-power electrical plasma-jet torch, which comprises: first body means formed of insulating plastic, said first body means having a large-diameter central passage therethrough, second body means formed of metal, said second body means also having a large-diameter central passage therethrough, means to mount said first and second body means adjacent each other and with said central passages in mutual alignment to thereby form a continuous passage, a slug holder formed of metal and inserted into one end of said continuous passage radially-inwardly of said first body means, an elongated electrode slug having its base end mounted in said slug holder at the inner end thereof, all portions of at least the forward end of said slug being formed of tungsten, said slug extending longitudinally of said passage a substantial distance forwardly from the inner end of said slug holder, said slug having a diameter smaller than that of said inner end of said slug holder, nozzle means formed of metal and inserted into the other end of said continuous passage radially-inwardly of said second body means, the inner end of said nozzle means being spaced longitudinally from said inner end of said slug holder, the inner end of said nozzle means encompassing said forward end of said slug, a gas-injector ring formed of heat resistant and electricallyinsulating material, said gas-injector ring being disposed concentrially around said slug between said inner ends of said slug holder and nozzle means, means to maintain a very high-current electric arc at least part of which is disposed in said nozzle means, the rear terminus of said arc being at said forward end of said slug, means to conduct arc gas to and through said gas-injector ring for inward flow around said slug and then forwardly through said nozzle means, said gas being heated by said arc and discharging from said torch at a high temperature and velocity, and means to effect cooling of said nozzle means and of said slug holder.
Claim 2
Dependent Claim
328 words
A high-power electrical plasma-jet torch, which comprises: first body means formed of insulating plastic, said first body means having a large-diameter central passage therethrough, second body means formed of metal, said second body means also having a large-diameter central passage therethrough, means to mount said first and second body means adjacent each other and with said central passages in mutual alignment to thereby form a continuous passage, a slug holder formed of metal and inserted into one end of said continuous passage radially-inwardly of said first body means, an elongated electrode slug having its base end mounted in said slug holder at the inner end thereof, all portions of at least the forward end of said slug being formed of tungsten, said slug extending longitudinally of said passage a substantial distance forwardly from the inner end of said slug holder, said slug having a diameter smaller than that of said inner end of said slug holder, nozzle means formed of metal and inserted into the other end of said continuous passage radially-inwardly of said second body means, the inner end of said nozzle means being spaced longitudinally from said inner end of said slug holder, the inner end of said nozzle means encompassing said forward end of said slug, a gas-injector ring formed of heat resistant and electricallyinsulating material, said gas-injector ring being disposed concentrially around said slug between said inner ends of said slug holder and nozzle means, means to maintain a very high-current electric arc at least part of which is disposed in said nozzle means, the rear terminus of said arc being at said forward end of said slug, means to conduct arc gas to and through said gas-injector ring for inward flow around said slug and then forwardly through said nozzle means, said gas being heated by said arc and discharging from said torch at a high temperature and velocity, and means to effect cooling of said nozzle means and of said slug holder.
Claim 3
Dependent Claim
18 words
The invention as claimed in claim 1, in which the nozzle passage through said nozzle means is supersonic.
Claim 4
Dependent Claim
39 words
The invention as claimed in claim 1, in which said arc-maintaining means is a D.C. source the negative terminal of which is connected to said slug holder and the positive terminal of which is connected to said nozzle means.
Claim 5
Dependent Claim
73 words
The invention as claimed in claim 1, in which said means to conduct arc gas to said gas-injector ring includes an annular space defined between the outer surface of said ring and a part of said first body means, and further includes circumferentially-spaced passages extending through said ring and communicating with said annular space and also with the space between the inner surface of said ring and the outer surface of said slug.
Claim 6
Dependent Claim
47 words
The invention as claimed in claim 1, in which said first body means comprises two annular components each formed of insulating plastic, and in which said mounting means mounts said two components of said first body means adjacent each other and also adjacent said second body means.
Claim 7
Dependent Claim
52 words
The invention as claimed in claim 5, in which said mounting means comprises a plurality of bolts which extend longitudinally of the torch through said two components of said first body means and also through said second body means, and which maintain the same in closely stacked relationship relativE to each other.
Claim 8
Dependent Claim
46 words
The invention as claimed in claim 5, in which said slug holder has a radially-outwardly extending flange which seats between adjacent portions of said two components of said first body means, whereby to maintain said slug holder in a predetermined desired position in said continuous passage.
Claim 9
Dependent Claim
58 words
The invention as claimed in claim 1, in which said inner end of said slug holder has a face which seats against a face at the rear side of said gas-injector ring, and in which said inner end of said nozzle means has a face which seats against a face at the forward side of said gas-injector ring.
Claim 10
Dependent Claim
35 words
The invention as claimed in claim 1, in which an O-ring is provided concentrically around said slug and is seated between said inner end of said slug holder and a portion of said gas-injector ring.
Claim 11
Dependent Claim
81 words
The invention as claimed in claim 1, in which said nozzle means defines a relatively large-diameter arc chamber around said forward end of said slug, and defines a smaller-diameter chamber forwardly of said forward end of said slug, said smaller-diameter chamber receiving the forward terminus of said arc when said arc-maintaining means applies a voltage between said nozzle means and said slug, and in which said nozzle means further comprises a relatively small-diameter nozzle passage extending forwardly from said smaller-diameter chamber.
Claim 12
Dependent Claim
17 words
The invention as claimed in claim 10, in which said last-named nozzle passage is a supersonic passage.
Claim 13
Dependent Claim
60 words
The invention as claimed in claim 1, in which said gas-injector ring is formed of ceramic, and in which said means to conduct arc gas to and through said gas-injector ring comprises a channel defined circumferentially around said gas-injector ring between said ring and an opposed portion of said first body means, and further comprises passages through said gas-injector ring.
Claim 14
Dependent Claim
91 words
The invention as claimed in claim 1, in which said first body means comprises two annular components each formed of insulating plastic and stacked relative to each other, and in which said means to conduct arc gas to and through said gas-injector ring comprises a tube which extends through the outer one of said two components and into a passage in the inner one of said two components, and in which an O-ring is provided around the portion of said tube which extends into said inner one of said two components.
Claim 15
Dependent Claim
77 words
The invention as claimed in claim 1, in which said means to maintain said electric arc and said means to effect cooling of said nozzle means and slug holder comprise means to conduct both water and electricity to said slug holder, means to conduct both water and electricity to said second body means and around said nozzle means, and means to conduct water from said second body means through said first body means to said slug holder.
Claim 16
Dependent Claim
30 words
The invention as claimed in claim 1, in which means are provided to removably mount said nozzle means in said continuous passage, whereby to facilitate replacement of said nozzle means.
Claim 17
Dependent Claim
17 words
The invention as claimed in claim 1, in which said gas-injector ring is formed of a ceramic.
Claim 18
Dependent Claim
40 words
The invention as claimed in claim 1, in which a handle is secured by screws to at least one of said first and second body means, and in which no portion of said handle encompasses either of said body means.
Claim 19
Dependent Claim
124 words
The invention as claimed in claim 1, in which said means to effect cooling of said nozzle means and slug holder comprises means to conduct water to said second body means circumferentially around said nozzle means, an O-ring disposed circumferentially around said inner end of said nozzle means between said nozzle means and said first body means, passage means extending through said first body means to conduct water from said second body means to an annular recess formed externally in said slug holder, a second O-ring mounted circumferentially around said inner end of said slug holder and seated between said inner end and a portion of said first body means, and means to pass water throUgh said slug holder from said annular recess therein.
Claim 20
Dependent Claim
71 words
The invention as claimed in claim 18, in which said inner end of said nozzle means is undercut to receive water from said second body means, whereby to interpose water between said first-mentioned O-ring and said slug, and in which said inner end of said slug holder is undercut to receive water from said annular recess in said slug holder and thereby interpose water between said second-mentioned O-ring and said slug.
Claim 21
Dependent Claim
45 words
The invention as claimed in claim 19, in which a third O-ring is provided between a rear surface of said gas-injector ring and said inner end of said slug holder, and third O-ring being cooled by water contained in said undercut in said slug holder.
Claim 22
Dependent Claim
103 words
The invention as claimed in claim 1, in which the means to cool said nozzle means comprises a plurality of circumferentially-spaced teeth extending radially-outwardly from said nozzle means and seated against an interior wall of said second means, said teeth being disposed radially-outwardly of the portion of said nozzle means forwardly adjacent said forward end of said slug, means to conduct water to an annular space formed forwardly of said teeth, whereby said water flows rearwardly through the gaps between said teeth, and in which means are provided to conduct water from the rear portion of said second body means to a drain.
Claim 23
Dependent Claim
56 words
Th invention as claimed in claim 21, in which an O-ring is provided between said nozzle means and said second body means at the forward portion of said second body means, and in which an undercut is provided in said nozzle means to interpose water between said O-ring and the nozzle passage through said nozzle means.
Claim 24
Dependent Claim
26 words
The invention as claimed in claim 1, in which said gas-injector ring includes gas passages so directed as to effect vortical gas flow around said slug.
Claim 25
Dependent Claim
21 words
The invention as claimed in claim 23, in which there are a multiplicity of such gas passages, each of small diameter.
Claim 26
Dependent Claim
25 words
The invention as claimed in claim 24, in which each of said passages is inclined forwardly relative to a radial plane perpendicular to said slug.
Claim 27
Dependent Claim
23 words
The invention as claimed in claim 1, in which said gas-injector ring includes a multiplicity of small-diameter gas flow passages circumferentially spaced therearound.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-07-08 | 1978-01-07 | 1978-07-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-07-08 | 1982-01-07 | 1982-07-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-07-08 | 1986-01-07 | 1986-07-09 | $7700.00 | Window Closed / Lapsed |