Patent US3638145A successfully refreshed from Google Patents.
US3638145A
Expired / Lapsed
US
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Electromechanical wave filter
Assignee: AT&T Inc
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Filing: 1969-12-15
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Granted: 1972-01-25
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Expires: 1989-12-15
Abstract
Abstract The specification described an electromechanical filter design which is an improvement over the ladder-type torsional filter of U.S. Pat. No. 3,064,213 issued to W. P. Mason on Nov. 13, 1962. Unwanted longitudinal resonances are eliminated by the use of a longitudinal reinforcing member. An improved mounting arrangement is described. It has also been found that the number of transducers necessary for effective operation of this filter can be reduced by one-half.
Inventors
- 👤 Emmanuel P Papadakis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 13:22
CPC Classifications
H; H03; H03H; H03H9/00; H03H9/02; H03H9/05; H03H9/0504; H03H9/46; H03H9/48; H03H9/50
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
161 words
An electromechanical wave filter comprising as a single planar body an elongated central member and a plurality of pairs of rib members, the pairs spaced along said central member at substantially equidistant positions and the ribs of each pair extending transversely away from said central member in opposite directions in a single plane, the filter further including at least one pair of electromechanical transducers affixed to each terminal pair of rib members, said transducers adapted to displace or to detect torsional displacement of the rib members with respect to the central member, the invention characterized in that the central member is constructed with a structurally reinforced portion extending substantially along its entire length so as to impart significantly greater longitudinal rigidity than the longitudinal rigidity of the rib members, thereby eliminating undesired longitudinal resonances from the central member, said structurally reinforced portion comprising a region having a thickness of at least 50 percent greater than the thickness of the rib members.
Claim 2
Dependent Claim
161 words
An electromechanical wave filter comprising as a single planar body an elongated central member and a plurality of pairs of rib members, the pairs spaced along said central member at substantially equidistant positions and the ribs of each pair extending transversely away from said central member in opposite directions in a single plane, the filter further including at least one pair of electromechanical transducers affixed to each terminal pair of rib members, said transducers adapted to displace or to detect torsional displacement of the rib members with respect to the central member, the invention characterized in that the central member is constructed with a structurally reinforced portion extending substantially along its entire length so as to impart significantly greater longitudinal rigidity than the longitudinal rigidity of the rib members, thereby eliminating undesired longitudinal resonances from the central member, said structurally reinforced portion comprising a region having a thickness of at least 50 percent greater than the thickness of the rib members.
Claim 3
Dependent Claim
166 words
An electromechanical wave filter comprising as a single planar body an elongated central member and a plurality of pairs of rib members, the pairs spaced along said central member at substantially equidistant positions and the ribs of each pair extending transversely away from said central member in opposite directions in a single plane, the filter further including at least one pair of electromechanical transducers affixed to each terminal pair of rib members, said transducers adapted to displace or to detect torsional displacement of the rib members with respect to the central member, the invention characterized in that the central member is constructed with a structurally reinforced portion extending substantially along its entire length so as to impart significantly greater longitudinal rigidity than the longitudinal rigidity of the rib members, thereby eliminating undesired longitudinal resonances from the central member, said structurally reinforced portion comprising a longitudinal crease in the central member, the crease having an average height at least equal to the thickness of the central member.
Claim 4
Dependent Claim
166 words
An electromechanical wave filter comprising as a single planar body an elongated central member and a plurality of pairs of rib members, the pairs spaced along said central member at substantially equidistant positions and the ribs of each pair extending transversely away from said central member in opposite directions in a single plane, the filter further including at least one pair of electromechanical transducers affixed to each terminal pair of rib members, said transducers adapted to displace or to detect torsional displacement of the rib members with respect to the central member, the invention characterized in that the central member is constructed with a structurally reinforced portion extending substantially along its entire length so as to impart significantly greater longitudinal rigidity than the longitudinal rigidity of the rib members, thereby eliminating undesired longitudinal resonances from the central member, said structurally reinforced portion comprising a longitudinal crease in the central member, the crease having an average height at least equal to the thickness of the central member.
Claim 5
Dependent Claim
193 words
An electromechanical wave filter comprising as a single planar body an elongated central member and a plurality of pairs of rib members, the pairs spaced along said central member at substantially equidistant positions and the ribs of each pair extending transversely away from said central member in opposite directions in a single plane, the filter further including at least one pair of electromechanicAl transducers affixed to each terminal pair of rib members, said transducers adapted to displace or to detect torsional displacement of the rib members with respect to the central member, the invention characterized in that the central member is constructed with a structurally reinforced portion extending substantially along its entire length so as to impart significantly greater longitudinal rigidity than the longitudinal rigidity of the rib members, thereby eliminating undesired longitudinal resonances from the central member and further including at least two support means for the filter, each support means comprising a pair of mounting members contacting the central strip of the filter at opposite sides thereof and at a position intermediate the longitudinal centerline of two pairs of rib members, said position being substantially at a torsional mode node point.
Claim 6
Dependent Claim
193 words
An electromechanical wave filter comprising as a single planar body an elongated central member and a plurality of pairs of rib members, the pairs spaced along said central member at substantially equidistant positions and the ribs of each pair extending transversely away from said central member in opposite directions in a single plane, the filter further including at least one pair of electromechanicAl transducers affixed to each terminal pair of rib members, said transducers adapted to displace or to detect torsional displacement of the rib members with respect to the central member, the invention characterized in that the central member is constructed with a structurally reinforced portion extending substantially along its entire length so as to impart significantly greater longitudinal rigidity than the longitudinal rigidity of the rib members, thereby eliminating undesired longitudinal resonances from the central member and further including at least two support means for the filter, each support means comprising a pair of mounting members contacting the central strip of the filter at opposite sides thereof and at a position intermediate the longitudinal centerline of two pairs of rib members, said position being substantially at a torsional mode node point.
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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) | 1975-01-24 | 1975-07-26 | 1976-01-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-24 | 1979-07-26 | 1980-01-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-24 | 1983-07-26 | 1984-01-25 | $7700.00 | Window Closed / Lapsed |