Fastener incorporating ultrasonic transducer

Claim 2

A fastener for fastening together structural members comprising: a shank having a head at one end and threads formed at the other end, a shallow opening formed in one end of said fastener and having a maximum depth from said one end of said fastener which is substantially less than the length of said fastener, and an acoustic transducer located in said opening and permanently secured therein with said transducer being acoustically coupled to said fastener, the entire portion of said fastener between said opening and the end of said fastener opposite said opening being formed of solid metal throughout.

Claim 3

The fastener of claim 1, wherein: said opening is formed in said head and has a depth less than the length of said head as measured along the longitudinal axis of said fastener.

Claim 4

The fastener of claim 1, wherein: said opening is formed in said other end of said shank.

Claim 5

The fastener of claim 1, wherein: said transducer comprises a disc shaped member secured in said opening such that its thin plane is substantially perpendicular to the axis of said shank.

Claim 6

The fastener of claims 1, 2, 3, or 4, wherein: said fastener is formed of metal, said transducer has electrodes formed at opposite ends thereof, one of said electrodes being in electrical contact with said fastener,

Claim 9

The method of claim 6 comprising the steps of: at a later date employing said transducer to make subsequent measurements.

Claim 10

The method of claim 7 wherein said subsequent measurements comprise: monitoring for flaws or cracks in said fastener.

Claim 11

The method of claim 8 wherein said subsequent measurements are obtained by: actuating said transducer to produce an acoustic pulse, and detecting for pulses reflected from the other end of said fastener.

Claim 12

The method of claim 8 wherein said subsequent measurements are obtained by: actuating said transducer to produce an acoustic pulse, and detecting for pulses reflected from surfaces other than from said other end of said fastener.

Claim 13

The method of claim 8 wherein said subsequent measurements are obtained by: detecting for acoustic pulses in said fastener.

Claim 14

The method of claim 7 wherein said subsequent measurements comprise: monitoring for acoustic emissions produced by said fastener or by surrounding structure.

Claim 15

The method of claim 6 wherein said measurements are obtained by: actuating said transducer to produce an acoustic pulse, and detecting for pulses reflected from the other end of said fastener.

Claim 16

A fastener for fastening together structural members, comprising: a shank having a head at one end and threads formed at the other end, an opening formed in one end only of said fastener, said opening being defined by side wall structure extending from said one end only of said fastener to a substantially flat surface substantially parallel to the end of said fastener opposite said opening, the maximum distance between said one end only of said fastener and said surface of said opening being substantially less than the length of said fastener, and an acoustic transducer located in said opening and permanently secured therein with said transducer being acoustically coupled to said fastener, the entire portion of said fastener between said opening and said end of said fastener opposite said opening being of solid metal throughout.

Claim 17

A fastener for fastening together structural members, comprising: a shank having a head at one end and threads formed at the other end, an opening formed in one end only of said fastener, said opening being defined by side wall structure extending from said one end only of said fastener to a substantially flat surface substantially parallel to the end of said fastener opposite said opening, the maximum distance between said one end only of said fastener and said surface of said opening being substantially less than the length of said fastener, and an acoustic transducer located in said opening and permanently secured therein with said transducer being acoustically coupled to said fastener, the entire portion of said fastener between said opening and said end of said fastener opposite said opening being of solid metal throughout.

Claim 18

The fastener of claim 14 wherein: said substantially flat surface of said opening is substantially perpendicular to the longitudinal axis of said fastener, said transducer has substantially flat opposite ends which are substantially parallel to said substantially flat surface of said opening and to said end of said fastener opposite said opening.

Claim 19

A fastener for fastening together structural members, comprising: a shank having a head at one end and threads formed at the other end, an opening formed in one end only of said fastener, said opening being defined by side wall structure extending from said one end only of said fastener to a surface which forms the end of said opening in said fastener, the maximum distance between said one end only of said fastener and said surface of said opening being substantially less than the length of said fastener, and an acoustic transducer located in said opening and permanently secured therein with said transducer being acoustically coupled to said fastener, said transducer having substantially flat opposite ends which are substantially perpendicular to the longitudinal axis of said shank the entire portion of said fastener between said opening and the end of said fastener opposite said opening being of solid metal throughout.

Claim 20

A fastener for fastening together structural members, comprising: a shank having a head at one end and threads formed at the other end, an opening formed in one end only of said fastener, said opening being defined by side wall structure extending from said one end only of said fastener to a surface which forms the end of said opening in said fastener, the maximum distance between said one end only of said fastener and said surface of said opening being substantially less than the length of said fastener, and an acoustic transducer located in said opening and permanently secured therein with said transducer being acoustically coupled to said fastener, said transducer having substantially flat opposite ends which are substantially perpendicular to the longitudinal axis of said shank the entire portion of said fastener between said opening and the end of said fastener opposite said opening being of solid metal throughout.

Claim 21

The fastener of claim 16, wherein: said substantially flat opposite ends of said transducer are substantially parallel to said end of said fastener opposite said opening.

Claim 22

The fastener of claims 14, 16, 17, or 15, wherein: said acoustic transducer is formed of a piezoelectric material.

Claim 23

The fastener of claims 16 or 17 wherein: one of said ends of said acoustic transducer is acoustically coupled to said surface of said opening.

Claim 24

The fastener of claims 1, 14 or 16 wherein: said fastener is intended for use on aircraft or on spacecraft.

Claim 25

The fastener of claims 14 or 16, wherein: said fastener is intended for use on aircraft or on spacecraft, said opening is formed in said head, said one end only of said fastener being the end of said head, said maximum distance between said end of said head and said surface of said opening being less than the length of said head as measured along the longitudinal axis of said fastener, said shank being of solid metal throughout its length.

Claim 26

A fastener, comprising: a shank having a head at one end and threads formed at the other end, a shallow opening formed in one end only of said fastener, an acoustic transducer located in said opening and permanently secured therein with said transducer being acoustically coupled to said fastener, said fastener being formed of metal with the portion of said fastener between said opening and the end of said fastener opposite said opening being of solid metal throughout.

Claim 27

A fastener, comprising: a shank having a head at one end and threads formed at the other end, a shallow opening formed in one end only of said fastener, an acoustic transducer located in said opening and permanently secured therein with said transducer being acoustically coupled to said fastener, said fastener being formed of metal with the portion of said fastener between said opening and the end of said fastener opposite said opening being of solid metal throughout.

Claim 28

The fastener of claims 1, 14 or 16 wherein: said transducer is located in said opening such that it may be used for pulse-echo measurements wherein when said transducer is pulsed, a transducer signal is generated which travels from said transducer through said fastener to said end of said fastener opposite said opening and back to said transducer at least once, the distance between said transducer and said end of said fastener opposite said opening being equal to a major portion of the length of said fastener such that when said signal is generated, it will travel through the entire gripping length of said fastener, including the portion of said shank next to said head, when traveling between said transducer and said end of said fastener opposite said opening.

Claim 29

The fastener of claim 23, wherein: said opening is formed in said head only.

Claim 30

A fastener, comprising: a shank having a head at one end and threads formed at the other end, an opening formed in said head from the end of said fastener coinciding with the end of said head, said opening being defined by side wall structure extending from said end of said fastener coinciding with the end of said head to a surface which forms the end of said opening in said fastener, the maximum distance between said end of said fastener coinciding with the end of said head and said surface of said opening being less than the length of said head as measured along the longitudinal axis of said fastener, an acoustic transducer located entirely in said opening and permanently secured therein, said fastener being formed of metal with the portion of said fastener between said opening and the end of said fastener opposite said opening being of solid metal throughout, said acoustic transducer being acoustically coupled to said surface of said opening, said acoustic transducer having two electrodes, one of said electrodes being electrically coupled to said fastener, the other of said electrodes being located to be electrically connectible to a utilization device.

Claim 31

A fastener, comprising: a shank having a head at one end and threads formed at the other end, an opening formed in said head from the end of said fastener coinciding with the end of said head, said opening being defined by side wall structure extending from said end of said fastener coinciding with the end of said head to a surface which forms the end of said opening in said fastener, the maximum distance between said end of said fastener coinciding with the end of said head and said surface of said opening being less than the length of said head as measured along the longitudinal axis of said fastener, an acoustic transducer located entirely in said opening and permanently secured therein, said fastener being formed of metal with the portion of said fastener between said opening and the end of said fastener opposite said opening being of solid metal throughout, said acoustic transducer being acoustically coupled to said surface of said opening, said acoustic transducer having two electrodes, one of said electrodes being electrically coupled to said fastener, the other of said electrodes being located to be electrically connectible to a utilization device.

Claim 34

A fastener, comprising: a shank having a head at one end and threads formed at the other end, a shallow opening formed in one end only of said fastener, an acoustic transducer located in said opening and permanently secured therein with said transducer being acoustically coupled to said fastener, said transducer being located in said opening such that it may be used for pulse-echo measurements wherein said transducer is pulsed, a transducer signal is generated which travels from said transducer through said fastener to the end of said fastener opposite said opening and back to said transducer at least once, the distance between said transducer and said end of said fastener opposite said opening being equal to a major portion of the length of said fastener such that when said signal is generated, it will travel through the entire gripping length of said fastener, including the portion of said shank next to said head, when traveling between said transducer and said end of said fastener opposite said opening, said fastener being formed of metal with the portion of said fastener between said opening and said end of said fastener opposite said opening being of solid metal throughout.

Claim 35

A fastener, comprising: a shank having a head at one end and threads formed at the other end, a shallow opening formed in one end only of said fastener, an acoustic transducer located in said opening and permanently secured therein with said transducer being acoustically coupled to said fastener, said transducer being located in said opening such that it may be used for pulse-echo measurements wherein said transducer is pulsed, a transducer signal is generated which travels from said transducer through said fastener to the end of said fastener opposite said opening and back to said transducer at least once, the distance between said transducer and said end of said fastener opposite said opening being equal to a major portion of the length of said fastener such that when said signal is generated, it will travel through the entire gripping length of said fastener, including the portion of said shank next to said head, when traveling between said transducer and said end of said fastener opposite said opening, said fastener being formed of metal with the portion of said fastener between said opening and said end of said fastener opposite said opening being of solid metal throughout.

Claim 36

A fastener, comprising: a shank having a head at one end and threads formed at the other end, a shallow opening formed in one end only of said fastener, an acoustic transducer located in said opening and permanently secured therein with said transducer being acoustically coupled to said fastener, said transducer being located in said opening such that it may be used for pulse-echo measurements wherein when said transducer is pulsed, a transducer signal is generated which travels from said transduer through said fastener to the end of said fastener opposite said opening and back to said transducer at least once, said fastener being formed of metal with the portion of said fastener between said opening and said end of said fastener opposite said opening being of solid metal throughout.

Claim 37

A fastener, comprising: a shank having a head at one end and threads formed at the other end, a shallow opening formed in one end only of said fastener, an acoustic transducer located in said opening and permanently secured therein with said transducer being acoustically coupled to said fastener, said transducer being located in said opening such that it may be used for pulse-echo measurements wherein when said transducer is pulsed, a transducer signal is generated which travels from said transduer through said fastener to the end of said fastener opposite said opening and back to said transducer at least once, said fastener being formed of metal with the portion of said fastener between said opening and said end of said fastener opposite said opening being of solid metal throughout.

Claim 38

The fastener of claim 37, wherein: said opening is formed in said head only.