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US4420826A Expired / Lapsed US ⏱️ 0.0 years remaining

Stress relief for flextensional transducer

Assignee: Lockheed Martin Corp
•
Filing: 1981-07-06
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Granted: 1983-12-13
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Expires: 2001-07-06
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Abstract

Abstract This invention is a device that permits a flextensional transducer to function after the flextensional transducer experiences a pressure equal to or greater than the pressure found at the survival depth of prior art flextensional transducers. The foregoing is achieved by not bonding at least one end of the transducer's piezoelectric stack to the transducer's shell and having the other end or ends of the piezoelectric stack held in the vicinity of the transducer's shell by a pair of guide rails, etc. This permits the transducer's shell to move away from at least one end of the piezoelectric stack at pressures equal to or greater than the pressure at which the stack would experience tensile stresses in a conventional flextensional design. Thus, the piezoelectric stack will not fracture since it receives no tensile stress. Hence, when the transducer experiences a hydrostatic pressure less than the pressure at the survival depth, the shell of the transducer will recontact the free end of the piezoelectric stack permitting the transducer to function.

Inventors

  • 👤 William J. Marshall, Jr.
  • 👤 Ronald P. White

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-31 12:40
CPC Classifications
G; G10; G10K; G10K9/00; G10K9/12; G10K9/121; B; B06; B06B; B06B1/00; B06B1/02; B06B1/06; B06B1/0607; B06B1/0611

Claims Analysis

Total Claims: 6
Claim 1
Independent Claim 107 words
In an underwater flextensional acoustical transducer comprising a cylindrical shell with an extendable driver stack disposed in an operable position between opposed sides of the shell in a longitudinally prestressed state, the improvement to prevent damage to the driver stack from negative stress resulting from overpressurization of the transducer comprising: (a) one of the ends of the driver stack being adapted to move longitudinally away from its respective side of the shell during an overpressurization condition of the transducer; and (b) guide means operably disposed adjacent said end and its respective side for guiding said end back into its operable position as said overpressurization condition is removed.
Claim 2
Dependent Claim 107 words
In an underwater flextensional acoustical transducer comprising a cylindrical shell with an extendable driver stack disposed in an operable position between opposed sides of the shell in a longitudinally prestressed state, the improvement to prevent damage to the driver stack from negative stress resulting from overpressurization of the transducer comprising: (a) one of the ends of the driver stack being adapted to move longitudinally away from its respective side of the shell during an overpressurization condition of the transducer; and (b) guide means operably disposed adjacent said end and its respective side for guiding said end back into its operable position as said overpressurization condition is removed.
Claim 3
Dependent Claim 33 words
The improvement of claim 1 wherein said guide means comprises: a pin on one of the two members and a groove on the other adapted to receive said pin in a sliding relationship.
Claim 4
Dependent Claim 23 words
The improvement of claim 1 wherein said guide means comprises: guide rails carried by the shell extending along the driver adjacent said end.
Claim 5
Dependent Claim 15 words
The improvement of claim 3 wherein: said end and said guide rails are tapered inwardly.
Claim 6
Dependent Claim 27 words
The improvement of claim 1 wherein said guide means comprises: an elastic calking material having a soft rubber-like quality disposed adjacent said end and its respective side.

References Cited (Backward Citations)

US3241099A Cited
US3274537A Cited
US3277433A Cited
US3258738A Cited
US3749948A Cited
US3813744A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1986-12-12 1987-06-13 1987-12-13 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1990-12-12 1991-06-13 1991-12-13 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1994-12-12 1995-06-13 1995-12-13 $7700.00 Window Closed / Lapsed

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