US3915381A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for applying particulate coating material to a work piece
Assignee: Southwest Research Institute
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Filing: 1973-10-26
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Granted: 1975-10-28
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Expires: 1993-10-26
Abstract
Abstract A system for applying particulate coating material to a work piece in which the particulate material is directed against the work piece in a series of pulses. Each pulse includes an initial step of feeding a charge of combustible gaseous mixture into a combustion chamber provided with an outlet nozzle. The combustible mixture is ignited and the outflow of gaseous mixture through the nozzle is constricted sufficiently to cause a rapid pressure rise during combustion to a peak value, followed by a period of falling pressure during continued outflow of the combusted mixture through the nozzle. A charge of the particulate coating material is injected into the combustion chamber for a brief period which terminates while the pressure in the chamber is at least a substantial proportion of the peak pressure. The outflow of combustion mixture and entrained particulate material is directed through the nozzle at high velocity against the work piece to cause the particulate material to form a coating on the work piece.
Inventors
- 👤 Jr Rosser Melton
- 👤 Jr John M Clark
- 👤 Ronald J Mathis
- 👤 Jr William D Weatherford
- 👤 Iii Charles D Wood
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 06:36
CPC Classifications
B; B05; B05B; B05B7/00; B05B7/0006; C; C23; C23C; C23C4/00; C23C4/12; C23C4/126
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
262 words
An apparatus for applying particulate coating material to a work piece comprising: a combustion chamber having a gas inlet and a restrictive gas outlet, valve means in the gas inlet for blocking flow of gas from the chamber out through the gas inlet during combustion in the combustion chamber, the combustion chamber having a cross sectional area substantially larger than that of the gas outlet such that a major portion of the gases will be retained in the combustion chamber by the restrictive gas outlet while the combustible gaseous mixture is deflagrated whereby the pressure within the combustion chamber will rise sharply as a result of such deflagration, fuel feed means for forming a combustible gaseous mixture in the chamber by forcing gases through the gas inlet into the combustion chamber, ignition means for igniting a combustible gaseous mixture in the combustion chamber, particle feed means for injecting a predetermined quantity of particulate coating material into gases of combustion in the combustion chamber, and control means for the valve means, fuel feed means, ignition means and particle feed means for respectively forming a combustible gaseous mixture in the combustion chamber, igniting the combustible gaseous mixture to produce a sharp increase in pressure in the combustion chamber, and injecting a predetermined quantity of particulate material into the chamber while a substantial portion of the gases of combustion are still in the combustion chamber, whereby the particulate material will be heated by the gases of combustion and accelerated by the gases of combustion issuing from the gas outlet for impact against a work piece.
Claim 2
Independent Claim
262 words
An apparatus for applying particulate coating material to a work piece comprising: a combustion chamber having a gas inlet and a restrictive gas outlet, valve means in the gas inlet for blocking flow of gas from the chamber out through the gas inlet during combustion in the combustion chamber, the combustion chamber having a cross sectional area substantially larger than that of the gas outlet such that a major portion of the gases will be retained in the combustion chamber by the restrictive gas outlet while the combustible gaseous mixture is deflagrated whereby the pressure within the combustion chamber will rise sharply as a result of such deflagration, fuel feed means for forming a combustible gaseous mixture in the chamber by forcing gases through the gas inlet into the combustion chamber, ignition means for igniting a combustible gaseous mixture in the combustion chamber, particle feed means for injecting a predetermined quantity of particulate coating material into gases of combustion in the combustion chamber, and control means for the valve means, fuel feed means, ignition means and particle feed means for respectively forming a combustible gaseous mixture in the combustion chamber, igniting the combustible gaseous mixture to produce a sharp increase in pressure in the combustion chamber, and injecting a predetermined quantity of particulate material into the chamber while a substantial portion of the gases of combustion are still in the combustion chamber, whereby the particulate material will be heated by the gases of combustion and accelerated by the gases of combustion issuing from the gas outlet for impact against a work piece.
Claim 3
Dependent Claim
80 words
The apparatus of claim 1 wherein the fuel feed means comprises: fuel-air carburetor means for producing a combustible mixture of fuel and air, a source of air at a super atmospheric pressure, and means connecting the source of air at super atmospheric pressure to the carburetor and the output of the carburetor to the gas Inlet of the combustion chamber, and wherein the valve means controls the admission of a fuel-air mixture from the carburetion means to the combustion chamber.
Claim 4
Dependent Claim
55 words
The apparatus of claim 2 wherein the fuel feed means has sufficient pressure capacity to force gas into the combustion chamber at a rate greater than the rate at which the gas escapes through the gas outlet to achieve a pressure substantially greater than atmospheric in the combustion chamber prior to combustion of the gases.
Claim 5
Dependent Claim
99 words
The apparatus of claim 2 wherein the fuel-air carburetion means comprises: a source of liquified natural gas, a mixing tank in fluid communication with said internal passage in said inlet valve housing, an air surge tank in fluid communication with a source of air under pressure and with said mixing tank for delivering air under pressure thereto, conduit means connecting said source of liquified propane gas and said mixing tank; and flow control means connected with said conduit means and with said air surge tank for regulating the proportions of air and propane gas fed to said mixing tank.
Claim 6
Dependent Claim
188 words
The apparatus of claim 1 wherein the particle feed means comprises: an injector housing having a closed injector chamber therein, an outlet port in said injector housing placing one end of said injector chamber in fluid communication with the interior of said injector chamber in fluid communication with the interior of said combustion chamber, an injector valve having, an injector valve head which in a closed position thereof closes said outlet port, actuating means connected with said injector valve head extending outwardly of said injector housing for selective movement of said injector valve head to an open position exposing said outlet ports; dispenser means connected with said injector housing for delivering a charge of the particulate material to said injector chamber in the region of said valve head; and pressure means in fluid communication with said injector chamber for supplying gas thereto at a pressure in excess of the peak pressure developed in said combustion chamber, whereby when said valve head is raised off said outlet port the pressure within said injector chamber is sufficient to inject the particulate material within said injector chamber into said combustion chamber.
Claim 7
Dependent Claim
24 words
The apparatus of claim 1 wherein the gas outlet is formed by an elongated nozzle of substantially constant diameter for accelerating the particulate material.
Claim 8
Dependent Claim
42 words
The apparatus of claim 6 wherein said combustion chamber and said nozzle are of generally circular cross section with the ratio of the internal diameter of said combustion chamber to the internal diameter of said nozzle being at least 5 to 1.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-10-27 | 1979-04-28 | 1979-10-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-27 | 1983-04-28 | 1983-10-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-27 | 1987-04-28 | 1987-10-28 | $7700.00 | Window Closed / Lapsed |