US4155122A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Light shield for welder's mask
Assignee: REVUE THOMMEN AG
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Filing: 1977-11-30
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Granted: 1979-05-22
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Expires: 1997-11-30
Abstract
Abstract A welder's helmet has a window with an upper section of invariable light-attenuation characteristics and a dimmable lower section comprising an ultraviolet filter, an infrared filter, and an electro-optical shutter such as a liquid crystal sandwiched between a polarizer and an analyzer. A control circuit including a UV-sensitive photocell, upon sensing a welding arc or flame, operates the shutter to reduce the amount of light transmitted through the lower section of the window.
Inventors
- 👤 Hermann Budmiger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 16:49
CPC Classifications
A; A61; A61F; A61F9/00; A61F9/04; A61F9/06; A61F9/065
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
104 words
A welder's eyeshield comprising: a headpiece provided with a window subdivided into a passive first section of constant light attenuation and a voltage-controlled second section of variable light transmissivity juxtaposed with said first section; photoelectric sensing means on said headpiece generating an output signal in response to incident radiation potentially damaging to the user's eyesight; and circuit means connecting said sensing means to said second section for maintaining same more highly transparent to visible rays than said first section in the absence of said output signal and for significantly reducing the light transmissivity of said second section in the presence of said output signal.
Claim 2
Dependent Claim
104 words
A welder's eyeshield comprising: a headpiece provided with a window subdivided into a passive first section of constant light attenuation and a voltage-controlled second section of variable light transmissivity juxtaposed with said first section; photoelectric sensing means on said headpiece generating an output signal in response to incident radiation potentially damaging to the user's eyesight; and circuit means connecting said sensing means to said second section for maintaining same more highly transparent to visible rays than said first section in the absence of said output signal and for significantly reducing the light transmissivity of said second section in the presence of said output signal.
Claim 3
Dependent Claim
18 words
A welder's eyeshield as defined in claim 1 wherein said first section is located above said second section.
Claim 4
Dependent Claim
26 words
A welder's eyeshield as defined in claim 2 wherein said first section is of greater height than said second section, said sections being substantially coextensive horizontally.
Claim 5
Dependent Claim
67 words
A welder's eyeshield as defined in claim 1 wherein said second section comprises a stack of substantially coextensive layers including an ultraviolet filter, an infrared filter, a polarizer, an analyzer, and an electro-optical element between said polarizer and said analyzer, said electro-optical element being switchable by said circuit means for changing the orientation of the plane of polarization of light passing from said polarizer toward said analyzer.
Claim 6
Dependent Claim
59 words
A welder's eyeshield as defined in claim 4 wherein said electro-optical element includes a liquid crystal of nematic type having a light-scattering effect in its de-energized state but passing plane-polarized light substantially unchanged in its energized state, said polarizer and analyzer having substantially parallel planes of polarization for giving a clear view of a workpiece in said energized state.
Claim 7
Dependent Claim
20 words
A welder's eyeshield as defined in claim 6 wherein said first section comprises an ultraviolet filter and an infrared filter.
Claim 8
Dependent Claim
31 words
A welder's eyeshield as defined in claim 7 wherein the optical density of said first section substantially equals that of said second section in the de-energized state of said liquid crystal.
Claim 9
Dependent Claim
27 words
A welder's eyeshield as defined in claim 1 wherein said sensing means comprises a photosensor selectively responsive to light rays outside the visible part of the spectrum.
Claim 10
Dependent Claim
18 words
A welder's eyeshield as defined in claim 8 wherein said photosensor includes a filter selectively passing ultraviolet light.
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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) | 1982-05-21 | 1982-11-20 | 1983-05-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-05-21 | 1986-11-20 | 1987-05-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-05-21 | 1990-11-20 | 1991-05-22 | $7700.00 | Window Closed / Lapsed |