USA As Represented by Secretary of the Navy

Other

William R Scott

Ignacio M Perez

Philip Bloomfield

William T Weist

Karen M McMahon

Charles S Ih

John M Carlyle

A fishing rod has a hollow interior in which is secured a semi-rigid line. The semi-rigid line is secured to a durable rubber band which in turn is secured to an interior base of the fishing rod, adjacent the handle. The opposite end of the semi-rigid line comprises a braided portion having a plastic anchor. A strike on the fishing line is thus transmitted through the fishing rod directly to the handle thereof.

Fishing rod with interior line

A Josephson break junction device suitable for highly sensitive electronic detecting systems. A superconductor film such as YBa.sub.2 Al.sub.3 O.sub.7 is deposited on a substrate such as a single-crystal MgO. The film is fractured across a narrow strip by at least one indentation in the substrate juxtaposed from the strip to form a break junction. A transducer is affixed to the substrate for applying a bending movement to the substrate to regulate the distance across the gap formed at the fracture to produce a Josephson turned junction effect. Alternatively, or in addition to the transducer, a bridge of a nobel metal is applied across the gap to produce a weak-link junction.

Josephson break junction thin film device

A Josephson break junction device suitable for highly sensitive electronic detecting systems. A superconductor film such as YBa.sub.2 Cu.sub.3 O.sub.7 is deposited on a substrate such as a simple-crystal MgO. The film is fractured across a narrow strip by at least one indentation in the substrate juxtaposed from the strip to form a break junction. A transducer is affixed to the substrate for applying a bending movement to the substrate to regulate the distance across the gap formed at the fracture to produce a Josephson turned junction effect. Alternatively, or in addition to the transducer, a bridge of a novel metal is applied across the gap to produce a weak-link junction.

Method for forming Josephson break junctions

A series of pulses are transmitted to a first laser and the same series of ulses through a time delay network to a second laser. Each laser provides pulses of light through separate diagonal mirrors and through respective transparent holograms. Each light beam is then brought into convergence by respective sides of a wedge shaped reflector and brought into spacially coincident focus by an imaging lens onto the surface of a sample under test. The two hologram transparencies are imaged spacially coincident but separated in time on the face of the sample. Thermal elastic waves produced by laser heating at the sample surface transform into a desired acoustic beam pattern determined by the nature of the wavefronts which the hologram transparency represents. The position of the coincident image on the sample may be moved by varying the time between the two pulses.

Laser generation of ultrasonic waveform reconstructions

A transducer is provided having interconnections between a conductive member and one side of a heat sensitive piezoelectric substrate such as PVF.sub.2 to or from which electric signals flow. The interconnections are positioned on one side of the substrate with the opposite side having a metalization under the interconnection attachment positions and in a continuous region therebetween. The interconnection includes adhesive material such as epoxy disposed between and attaching an electrically conductive member to one side of the substrate and a single contiguous electrically conductive coating applied to adjacent portions of these two members to electrically connect them. Since both interconnections are positioned on one side of the substrate the transducer is adhesively fastenable to operational structure with a strong bond line, permits lead attachment after mounting and prevents lead shortout. Various electrode shapes, sizes and patterns may be constructed to allow power channeling and to produce focusing of the transducer signal.

Single-side connected transducer

A mechanical and electrical connection for a piezoelectric member of polyic material such as polyvinylidene fluoride, and method for forming such a connection. To form the connection, the piezoelectric member is first masked to prevent a preselected portion of its surface from being coated during subsequent coating operations. An electrically conductive member such as a lead wire or a solderable terminal is then attached to the nonmasked area of the piezoelectric member with adhesive such as epoxy. The masked piezoelectric member, the electrically conductive member, and (incidentally) the mask are then coated with a conductive coating such as sputtered gold to electrically connect the conductive member to the piezoelectric member. The mask can now be removed from the piezoelectric member if desired, although it can be left in place as a convenient vise. If the conductive member is a wire, adjacent portions of the wire and the piezoelectric member can now be coated with additional epoxy to provide heat dissipation for and protect the electrical connection provided by the conductive coating, and to insure mechanical strength of the contact. If the conductive member is a terminal strip or solderable terminal, a wire can now be soldered to the conductive coating at the terminal using low temperature solder. The solder joint can then be coated with silver-filled paint to produce a lower current density and lower contact resistance in the vicinity of the contact.

Method for making a piezoelectric transducer

Electrical connection

Apparatus and method for producing maps of thickness or elastic constant iations of nominally plane sheet or plate materials. Amplitude variation at a set frequency on a normal resonance peak is recorded to determine resonance peak variation and thus specimen thickness or elastic constant variation. A mechanical scanner moves a transducer across the material submerged in a water tank for performing an ultrasonic C-scan. A transmitter or pulse generator repeatedly pulses the transducer to produce a focused narrow pulse of ultrasound which reverberates within the material. Echoes from the material in response to the pulse are received by the same or another synchronously moving transducer, whose resulting signal then passes through a gate, which removes extraneous signals and selects the number of multiple echoes and thus amplitude range desired, and a variable filter controlled by a function generator which selects the desired frequency, to a pen recorder. The desired frequency is selected at or near a resonance peak for the material. The variable filter produces a signal in the desired narrow frequency band whose amplitude variation is indicative of variation in the material's properties with position of the transducer. The amplitude of the gated filtered signal is used to control the intensity of the recorder, which moves synchronous with the motion of the transducer. The recorder produces a map of the material at the desired frequency.

Material scanning apparatus

A device for acquiring and displaying acoustic emission fatigue data so as to facilitate the interpretation of dynamic micromechanical failure processes in materials. The load on a specimen under cyclic loading is monitored by a load cell whose output is sent to a cycle counter. The specimen is also monitored by a transducer which senses acoustic emissions. The signal produced by the transducer passes through a preamplifier, filter, amplifier and threshold detector to a pulse generator whose output is connected to the intensity modulation input of an oscilloscope or other cartesian coordinate arraying device. The load cell output is also connected to the vertical deflection input of the oscilloscope. The counter output is connected to the horizontal deflection input of the oscilloscope. Every time that the transducer detects an acoustic emission event, that event is represented on the oscilloscope in a two-dimensional cartesian coordinate system as a dot whose ordinate corresponds to the instantaneous load (derived from the load cell) and whose abscissa corresponds to the number of elapsed fatigue cycles (derived from the counter) at the time the event occurred, resulting in the simultaneous recording of the relationship between sample load, acoustic emission rate and number of fatigue cycles. By placing a screen splitter on the vertical deflection input to the oscilloscope, separate records of emissions under rising loads and under falling loads are produced.

Acoustic emission fatigue analyzer

A method and apparatus for determining fatigue in a structural part. The fatigue sensor comprises, for example, a thin silver zinc film affixed to a structural member that is to be monitored for fatigue damage. Upon sufficient flexing or other cold working, the silver zinc film undergoes a color change, pink to silver, to thereby indicate that the structural member has reached predetermined fatigue levels.

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Doylestown, PA, United States of America

William R Scott