Patent US4836689A successfully refreshed from Google Patents.
US4836689A
Expired / Lapsed
US
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Asymmetric purge air system for cleaning a lens
Assignee: Rosemount Inc
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Filing: 1987-09-04
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Granted: 1989-06-06
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Expires: 2007-09-04
Abstract
Abstract A purging air flow system for passing air over a lens to keep it clean and free from particulate contaminants and also for providing a positive flow of air away from the lens has baffles which cause a flow across the lens that is not symmetrical to avoid a dead air or stagnation zone in the center of the lens. The air supply used for such purging is controlled adequately so the flow changes direction and particles are removed from the main flow of purge air by inertial separation prior to the time the air contacts the lens. Such air entrained particles might otherwise deposit on the lens. A flow control orifice also may provide a secondary flow to carry the particles separated from the main flow out of the flow passageway.
Inventors
- 👤 Richard J. O'Brien
- 👤 Douglas C. Myhre
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 10:48
CPC Classifications
G; G01; G01J; G01J5/00; G01J5/0088; G01J5/02; G01J5/04; G01J5/041; G01J5/05; G01J5/051; G01J5/08; G01J5/0806; G01J5/0818; G01J5/0893; G02; G02B; G02B27/00; G02B27/0006; G03; G03F; G03F7/00; G03F7/70; G03F7/708; G03F7/70908; G03F7/70933
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
182 words
An instrument for sensing radiation representative of a parameter in a particle suspension and for providing an output indicative of the parameter, the instrument receiving a supply of pressurized fluid, comprising: port means disposed on the instrument and opening to the parameter source for receiving the radiation; sensing means coupled to the port means for sensing the received radiation and for providing the output; window means disposed between the port means and the sensing means for transmitting the radiation therethrough and for shielding the sensing means from the particle suspension, the window means having a window surface with a central axis normal to the window surface, for transmitting radiation to the sensing means exposed to the suspension; and purge means disposed in the instrument for receiving the pressurized fluid and having openings arranged around the circumference of the window surface for directing flows of the pressurized fluid having an axially asymmetric flow pattern onto the window surface, generating an unstable flow pattern of the pressurized fluid on the window surface such that particles are removed from substantially all of the window surface.
Claim 2
Dependent Claim
182 words
An instrument for sensing radiation representative of a parameter in a particle suspension and for providing an output indicative of the parameter, the instrument receiving a supply of pressurized fluid, comprising: port means disposed on the instrument and opening to the parameter source for receiving the radiation; sensing means coupled to the port means for sensing the received radiation and for providing the output; window means disposed between the port means and the sensing means for transmitting the radiation therethrough and for shielding the sensing means from the particle suspension, the window means having a window surface with a central axis normal to the window surface, for transmitting radiation to the sensing means exposed to the suspension; and purge means disposed in the instrument for receiving the pressurized fluid and having openings arranged around the circumference of the window surface for directing flows of the pressurized fluid having an axially asymmetric flow pattern onto the window surface, generating an unstable flow pattern of the pressurized fluid on the window surface such that particles are removed from substantially all of the window surface.
Claim 3
Dependent Claim
28 words
The instrument of claim 1 wherein the purge means comprises ports disposed adjacent to the window surface for providing radial flow of the fluid onto the window surface.
Claim 4
Dependent Claim
41 words
The instrument of claim 2 wherein the port means are positioned radially around the window surface such that at least one port providing substantial flow is positioned so its central radial axis is non-coincidental with the central axis of other ports.
Claim 5
Dependent Claim
58 words
The instrument of claim 2 wherein the window surface has a central region disposed in the center of the window surface and spaced away from the ports and wherein the radial flow of the fluid is controlled to have an asymmetric magnitude such that there is substantial flow of fluid over the central region of the window surface.
Claim 6
Dependent Claim
34 words
The instrument of claim 4 wherein the radial flow has a low flow zone where generally opposite direction flows meet on the window surface and which zone moves with respect to the window surface.
Claim 7
Dependent Claim
34 words
The instrument of claim 4 wherein the radial flow has a low flow zone where generally opposite direction flows meet on the window surface and which zones moves with respect to the window surface.
Claim 8
Dependent Claim
175 words
An instrument for sensing radiation representative of a parameter in a particle suspension and for providing an output indicative of the parameter, the instrument receiving a supply of pressurized fluid, comprising: port means disposed on the instrument and opening to the parameter source for receiving the radiation; sensing means coupled to the port means for sensing the received radiation and for providing the output; window means disposed between the port means and the sensing means for transmitting the radiation therethrough and for shielding the sensing means from the particle suspension, the window means having a window surface for transmitting radiation to the sensing means exposed to the suspension; and purge means defining a plurality of radially spaced ports around the periphery of the window surface and means for providing a flow of the pressurized fluid inwardly from the ports toward center portions of the window surface, the ports being asymmetrical for providing an unstable flow of the pressurized fluid onto the window surface such that particles are removed from substantially all of the window surface.
Claim 9
Dependent Claim
175 words
An instrument for sensing radiation representative of a parameter in a particle suspension and for providing an output indicative of the parameter, the instrument receiving a supply of pressurized fluid, comprising: port means disposed on the instrument and opening to the parameter source for receiving the radiation; sensing means coupled to the port means for sensing the received radiation and for providing the output; window means disposed between the port means and the sensing means for transmitting the radiation therethrough and for shielding the sensing means from the particle suspension, the window means having a window surface for transmitting radiation to the sensing means exposed to the suspension; and purge means defining a plurality of radially spaced ports around the periphery of the window surface and means for providing a flow of the pressurized fluid inwardly from the ports toward center portions of the window surface, the ports being asymmetrical for providing an unstable flow of the pressurized fluid onto the window surface such that particles are removed from substantially all of the window surface.
Claim 10
Dependent Claim
31 words
The instrument of claim 7 wherein; the ports are separated by a pluraity of walls and at least two of the walls having different annular length to provide the asymmetric flow.
Claim 11
Dependent Claim
40 words
The instrument of claim 7, and passageway means for the pressurized fluid formed to cause an abrupt change in direction of flow to inertially separate particles from the pressurized fluid prior to flow of the pressurized fluid through the ports.
References Cited (Backward Citations)
US3436965A
Cited
US3626758A
Cited
US4037473A
Cited
US3846080A
Cited
US3861198A
Cited
US3877780A
Cited
US4018513A
Cited
US4118985A
Cited
SU584195A1
Cited
FR2365108A1
Cited
GB1559185A
Cited
US4306835A
Cited
US4459043A
Cited
US4435093A
Cited
GB2130717A
Cited
WO1987005390A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-06-05 | 1992-12-05 | 1993-06-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-06-05 | 1996-12-05 | 1997-06-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-06-05 | 2000-12-05 | 2001-06-06 | $7700.00 | Window Closed / Lapsed |