US4247838A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Expansion joint for wave guides
Assignee: ANOYME DITE Ste
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Filing: 1979-03-26
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Granted: 1981-01-27
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Expires: 1999-03-26
Abstract
Abstract The expansion joint includes a first component and a second component which have the same inside dimensions as the wave guide and are free to move longitudinally with respect to each other, the first component having exclusively a wave guide structure, the second component including a trap positioned at least partially between said components and outside the first component, the electric length of said trap being equal to half the wavelength of the central frequency transmitted by the wave guide, said components being separated longitudinally at the trap by a distance which varies when the length of the wave guide varies. The trap can be folded to reduce its bulk. Application to long wave guides.
Inventors
- 👤 Michel Sirel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 02:51
CPC Classifications
H; H01; H01P; H01P1/00; H01P1/30; H01P1/06; H01P1/061
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
219 words
An expansion joint for wave guides, said expansion joint including first and second aligned components which have the same inside dimensions as the wave guide and which are free to move longitudinally with respect to each other, the improvement wherein said first component comprises a tube, said second component includes a trap positioned at least partially between said components and radially outside the first component, the electric length of said trap being equal to half the wavelength of the central frequency transmitted by the wave guide, and means for separating said components longitudinally at the trap by a distance which varies as the length of the wave guide varies, and wherein said trap is folded so as to obtain two transmission lines which have the same electric length, and said trap includes a first transmission line constituted by a space comprised between the first component and the first longitudinal branch of the second component, a second transmission line constituted by a space comprised between said first branch and said second longitudinal branch, one of whose ends has a radially inwardly turned lip facing said other surface of said first component and covering one end of said first branch, and wherein said second transmission line is wider than that of the first transmission line and having therefore a greater impedance.
Claim 2
Dependent Claim
219 words
An expansion joint for wave guides, said expansion joint including first and second aligned components which have the same inside dimensions as the wave guide and which are free to move longitudinally with respect to each other, the improvement wherein said first component comprises a tube, said second component includes a trap positioned at least partially between said components and radially outside the first component, the electric length of said trap being equal to half the wavelength of the central frequency transmitted by the wave guide, and means for separating said components longitudinally at the trap by a distance which varies as the length of the wave guide varies, and wherein said trap is folded so as to obtain two transmission lines which have the same electric length, and said trap includes a first transmission line constituted by a space comprised between the first component and the first longitudinal branch of the second component, a second transmission line constituted by a space comprised between said first branch and said second longitudinal branch, one of whose ends has a radially inwardly turned lip facing said other surface of said first component and covering one end of said first branch, and wherein said second transmission line is wider than that of the first transmission line and having therefore a greater impedance.
Claim 3
Dependent Claim
42 words
An expansion joint according to claim 1, wherein a flexible insulating part is fixed on one side to a flange of said component and the other side to said lip of said second component so as to provide dust proof sealing therebetween.
Claim 4
Dependent Claim
33 words
An expansion joint according to claim 2, wherein a metal hood completely covers said flexible insulating part and said hood includes two parts which are free to slide with respect to each other.
Claim 5
Dependent Claim
27 words
An expansion joint according to claim 1, wherein its cross-section is rectangular and the trap is mounted on each of the large sides of said rectangular cross-section.
Claim 6
Dependent Claim
27 words
An expansion joint according to claim 4, wherein a plate of plastics material is interposed between each of the small sides of the first and second components.
Claim 7
Dependent Claim
51 words
An expansion joint according to claim 1, wherein both components are connected together by jacks so as to keep them at a predetermined distance apart during installation, said distance being a function of the ambient temperature, and means for removing said jacks when the components are installed in the wave guide.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-01-27 | 1984-07-28 | 1985-01-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-01-27 | 1988-07-28 | 1989-01-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-01-27 | 1992-07-28 | 1993-01-27 | $7700.00 | Window Closed / Lapsed |