US4482513A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of molding foam/aluminum flake microwave lenses
Assignee: Hughes Missile Systems Co
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Filing: 1983-07-22
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Granted: 1984-11-13
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Expires: 2003-07-22
Abstract
Abstract A microwave lens is constructed of a homogeneous body of closed cell rigid polyurethane foam with aluminum flakes dispursed throughout and having a configuration defining an axis and opposed lens surfaces. The method of the invention includes selecting a mold having a cavity of the appropriate configuration, preheating the mold, and filling the mold with a mixture of low density polyurethane foam components and fine aluminum flakes evenly dispersed throughout the foam structure allowing the mixture to cool and form a body of the appropriate configuration.
Inventors
- 👤 Craig R. Auletti
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 16:33
CPC Classifications
H; H01; H01Q; H01Q15/00; H01Q15/02; B; B29; B29C; B29C44/00; B29C44/34; B29C44/36; B29C44/38; B29C44/40; B29K; B29K2075/00; B29K2105/00; B29K2105/06; B29K2105/16; B29K2705/00; B29K2705/02; B29L; B29L2031/00; B29L2031/34; B29L2031/3456; Y; Y10; Y10S; Y10S425/00; Y10S425/812
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
109 words
A method of making a microwave lens comprising the steps of: selecting a mold having a cavity of the desired configuration for the controlled directing of microwaves; polishing the walls of said cavity; preheating said mold to a predetermined temperature; selecting and preparing a mixture consisting of low density polyurethane foam components and fine aluminum flakes; filling said mold cavity with said mixture; selecting a venting cover having a predetermined venting characteristic; installing the cover on the mold cavity; allowing the mold to cool and simultaneously allowing the contents to expand and cool; opening said mold by removing said venting cover; and removing the formed lens from the mold.
Claim 2
Independent Claim
109 words
A method of making a microwave lens comprising the steps of: selecting a mold having a cavity of the desired configuration for the controlled directing of microwaves; polishing the walls of said cavity; preheating said mold to a predetermined temperature; selecting and preparing a mixture consisting of low density polyurethane foam components and fine aluminum flakes; filling said mold cavity with said mixture; selecting a venting cover having a predetermined venting characteristic; installing the cover on the mold cavity; allowing the mold to cool and simultaneously allowing the contents to expand and cool; opening said mold by removing said venting cover; and removing the formed lens from the mold.
Claim 3
Dependent Claim
24 words
The method of claim 1 wherein the step of polishing the walls of said mold includes polishing said cavity to a 6 micron finish.
Claim 4
Dependent Claim
45 words
The method of claim 1 including the steps of preparing said mixture of polyurethane foam and aluminum by the steps of mixing 13 parts of aluminum flakes within 30 parts isocyanate and then adding 30 parts polyol and mixing for a predetermined period of time.
Claim 5
Dependent Claim
39 words
The method of claim 1 wherein the step of selecting the mold includes selecting the vent cover to provide uniform venting over the entire mold for uniformly expanding the material in a manner to provide a homogeneous lens body.
Claim 6
Dependent Claim
47 words
The method of claim 4 wherein the step of selecting the mold cover includes selecting a cover having inner and outer concentric circles of vent holes arranged along a radius and at an angle of 45 degrees to one another around the center axis of the mold.
Claim 7
Dependent Claim
21 words
The method of claim 1 wherein the polyurethane foam components are selected to produce an expandable closed cell rigid polyurethane foam.
Claim 8
Dependent Claim
24 words
The method of claim 6 including the step of selecting said aluminum flakes comprises selecting said flakes to have a mesh of approximately 325.
Claim 9
Dependent Claim
33 words
The method of claim 7 wherein the step of heating said mold includes heating said mold to a temperature of about 105 degrees F. for a period of time of about twenty minutes.
Claim 10
Dependent Claim
34 words
The method of claim 6 including the steps of forming a first portion of said lens having a first dielectric constant, and forming a second portion of said lens having a second dielectric constant.
Claim 11
Dependent Claim
85 words
The method of claim 9 wherein: the step of forming a first portion of said lens having a first dielectric constant includes the step of selecting a venting cover having a plug attached for extending into the mold cavity; and the step of forming a second portion of said lens having a second dielectric constant includes removing said cover and filling the cavity formed by said plug with a mixture of low density foam components and aluminum flakes selected to provide the second dielectric constant.
Claim 12
Dependent Claim
24 words
The method of claim 10 including the step of selecting the dielectric constant by adjusting the percentage weight of aluminum flakes in said mixture.
Claim 13
Dependent Claim
35 words
The method of claim 8 wherein the step of selecting and preparing said mixture of polyurethane foam components and fine aluminum flakes includes selecting the quantity of aluminum flakes to provide a predetermined dielectric constant.
Claim 14
Independent Claim
211 words
A method of making a microwave lens having at least one curved surface for the controlled directing of microwaves apprising the steps of: selecting a mold having a cavity of a predetermined configuration for shaping a lens for controlled passage of microwaves; polishing the walls of said cavity to a finish of about six micron; preheating said mold to a predetermined temperature of about 105° Fahrenheit for a period of about 20 minutes; selecting and preparing a mixture of a low density polyurethane foam components for producing an expandable closed cell rigid polyurethane foam and a quantity of metal flakes for establishing a lens of a predetermined dielectric; placing a selected quantity of said mixture in said mold cavity; selecting a venting mold cover having inner and outer concentric circles of vent holes arranged along a radius at an angle of about 45° to one another around the center axis of said mold to provide uniform venting of the entire mold for uniformly expanding the material in a manner to provide a lens body; installing the cover on the mold cavities; simultaneously allowing the contents of said mold cavity to expand and cool while allowing the mold to cool; and opening said mold and removing the resulting lens from the mold.
Claim 15
Independent Claim
211 words
A method of making a microwave lens having at least one curved surface for the controlled directing of microwaves apprising the steps of: selecting a mold having a cavity of a predetermined configuration for shaping a lens for controlled passage of microwaves; polishing the walls of said cavity to a finish of about six micron; preheating said mold to a predetermined temperature of about 105° Fahrenheit for a period of about 20 minutes; selecting and preparing a mixture of a low density polyurethane foam components for producing an expandable closed cell rigid polyurethane foam and a quantity of metal flakes for establishing a lens of a predetermined dielectric; placing a selected quantity of said mixture in said mold cavity; selecting a venting mold cover having inner and outer concentric circles of vent holes arranged along a radius at an angle of about 45° to one another around the center axis of said mold to provide uniform venting of the entire mold for uniformly expanding the material in a manner to provide a lens body; installing the cover on the mold cavities; simultaneously allowing the contents of said mold cavity to expand and cool while allowing the mold to cool; and opening said mold and removing the resulting lens from the mold.
Claim 16
Dependent Claim
30 words
The method of claim 13 including selecting and preparing said mixture to produce a dielectric constant in a range from 1.15 to about 5.0 and a substantially constant loss tangent.
Claim 17
Dependent Claim
19 words
The method of claim 14 wherein said metal flakes are selected to be aluminum flakes of approximately 325 mesh.
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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) | 1987-11-13 | 1988-05-14 | 1988-11-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-11-13 | 1992-05-14 | 1992-11-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-11-13 | 1996-05-14 | 1996-11-13 | $7700.00 | Window Closed / Lapsed |