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US3604789A Expired / Lapsed US ⏱️ 0.0 years remaining

Aerodynamic window

Assignee: RTX Corp
•
Filing: 1968-05-23
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Granted: 1971-09-14
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Expires: 1988-05-23
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Abstract

Abstract An output beam is emitted from a gas-dynamic laser and directed through an opening or port to the atmosphere. The gas pressure on the side of the opening from which the laser beam is emitted is below atmosphere (for example, 0.10 atmosphere) and the pressure on the outside of the opening is atmospheric. To prevent flow in said opening between the atmospheric side of the opening and the low-pressure side of the opening in the gas laser, the beam is directed through an aerodynamic window. The aerodynamic window is an opening formed in the sidewall of a passageway and placed in line with the inlet to the passageway so that a laser beam can pass through the opening and out the inlet, the path being unobstructed by attenuating or disturbing materials. The passageway is formed having an inlet section with a short section of constant area and a faired inlet mouth. At the downstream end of the inlet section the passageway bends at an angle forming a sharp corner and extending away from the proposed path of the laser beam. This side of the passageway extends as a straight line. The side opposite the straight side extends on in the same direction as an extension of the short section of constant area and this curves gradually towards the straight side until it becomes parallel therewith. The passageway then extends until it is connected to suction means to obtain the desired pressure characteristic in the passageway so that ambient air does not flow into the opening in the sidewall of the passageway and into the laser cavity.

Inventors

  • 👤 George H Mclafferty

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-29 19:42
CPC Classifications
H; H01; H01S; H01S3/00; H01S3/02; H01S3/03; H01S3/034; H01S3/0343

Claims Analysis

Total Claims: 7
Claim 1
Independent Claim 145 words
A device for providing an aerodynamic window for the passage of a beam between two regions at different pressures including in combination, a passageway having an inlet and outlet, divergent nozzle means having one side extending at an angle from said outlet in approximately a straight line and the other side extending coextensively with the outlet and curving gradually to form a diverging section with said straight side thereby forming a desired expansion ratio, duct means extending from the expansion end of the nozzle means, suction means connected to the free end of said duct means for creating a negative pressure therein, an opening in said duct means adjacent the nozzle means, said suction means sucking the fluid from the higher pressure region into said nozzle means and duct means so that a surface of stream lines appears across said opening in said duct means.
Claim 2
Independent Claim 145 words
A device for providing an aerodynamic window for the passage of a beam between two regions at different pressures including in combination, a passageway having an inlet and outlet, divergent nozzle means having one side extending at an angle from said outlet in approximately a straight line and the other side extending coextensively with the outlet and curving gradually to form a diverging section with said straight side thereby forming a desired expansion ratio, duct means extending from the expansion end of the nozzle means, suction means connected to the free end of said duct means for creating a negative pressure therein, an opening in said duct means adjacent the nozzle means, said suction means sucking the fluid from the higher pressure region into said nozzle means and duct means so that a surface of stream lines appears across said opening in said duct means.
Claim 3
Dependent Claim 34 words
A combination as set forth in claim 1 wherein a distinct edge is formed where the one side of said convergent nozzle means extends from said outlet so that a Prandtl-Meyer expansion fan results.
Claim 4
Dependent Claim 32 words
A combination as set forth in claim 1 wherein said opening is aligned with said passageway so that a beam can pass directly in a straight line through both opening and passageway.
Claim 5
Dependent Claim 37 words
A combination as set forth in claim 1 wherein said desired expansion ratio is selected to match the pressure of the exit of the nozzle means with the pressure of the fluid at the low pressure region.
Claim 6
Independent Claim 217 words
A device for providing an aerodynamic window for the passage of a beam between two regions at different pressures including in combination, a passageway having an inlet and outlet, divergent-nozzle means, having one side extending at an angle from said outlet in a straight line and the other side extending coextensively with the outlet and curving gradually to form a diverging section with said straight side thereby forming a desired expansion ratio, duct means extending from the Expansion end of the nozzle means, suction means connected to the free end of said duct means for creating a negative pressure therein, an opening in said duct means adjacent the nozzle means, a device for emitting a beam therefrom having a low pressure region therein, said device having a hole for the passage of the beam, a conduit connection the device to said duct to carry the beam, said closed passage extending from around the hole of said device to around the opening in said duct means, said conduit being in line with the passageway so that said beam passes through said conduit and said passageway, said suction means sucking the fluid from the higher pressure region into said nozzle means and duct means so that a surface of stream lines appears across said opening in said duct means.
Claim 7
Independent Claim 217 words
A device for providing an aerodynamic window for the passage of a beam between two regions at different pressures including in combination, a passageway having an inlet and outlet, divergent-nozzle means, having one side extending at an angle from said outlet in a straight line and the other side extending coextensively with the outlet and curving gradually to form a diverging section with said straight side thereby forming a desired expansion ratio, duct means extending from the Expansion end of the nozzle means, suction means connected to the free end of said duct means for creating a negative pressure therein, an opening in said duct means adjacent the nozzle means, a device for emitting a beam therefrom having a low pressure region therein, said device having a hole for the passage of the beam, a conduit connection the device to said duct to carry the beam, said closed passage extending from around the hole of said device to around the opening in said duct means, said conduit being in line with the passageway so that said beam passes through said conduit and said passageway, said suction means sucking the fluid from the higher pressure region into said nozzle means and duct means so that a surface of stream lines appears across said opening in said duct means.

References Cited (Backward Citations)

AT232294B Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1974-09-13 1975-03-15 1975-09-14 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1978-09-13 1979-03-15 1979-09-14 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1982-09-13 1983-03-15 1983-09-14 $7700.00 Window Closed / Lapsed

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