Ultrasonic load indicating member
First Claim
1. A load indicating member comprising:
- a shank, which, when stressed longitudinally, is subject to elastic deformation such that one portion thereof moves relative to another portion thereof;
a first generally flat surface formed adjacent one longitudinal end of said shank;
first electrode means permanently, mechanically, electrically, and acoustically interconnected with said shank;
piezoelectric film means permanently, mechanically, and electrically interconnected with said first electrode means;
second electrode means permanently, mechanically, and electrically interconnected with said piezoelectric means and electrically isolated from said head and said first electrode means, such that said electrode means and said piezoelectric means cooperate to form an ultrasonic transducer; and
a second generally flat surface formed on said shank at a location remote from said one longitudinal end of said shank, said second flat surface being generally coplanar with said first flat surface and spaced a predetermined distance therefrom.
1 Assignment
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Accused Products
Abstract
A method of measuring the load in a member subjected to longitudinal stress, a load measuring device and a fastener tightening device using the method of measuring, a load indicating member and a load indicating fastener for use in conjunction with the method of measuring, a method of making the load indicating fastener, a method of making the load indicating fastener, a method of tightening the load indicating fastener and a transducer for instrumenting a load bearing member are each disclosed and claimed. A thin piezoelectric sensor consisting of a piezoelectric film sandwiched between two thin electrodes is permanently mechanically and acoustically coupled to the upper surface of a member and is used to determine the length, tensile load, stress, or other tensile load dependant characteristic of the member by ultrasonic techniques.
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Citations
50 Claims
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1. A load indicating member comprising:
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a shank, which, when stressed longitudinally, is subject to elastic deformation such that one portion thereof moves relative to another portion thereof; a first generally flat surface formed adjacent one longitudinal end of said shank; first electrode means permanently, mechanically, electrically, and acoustically interconnected with said shank; piezoelectric film means permanently, mechanically, and electrically interconnected with said first electrode means; second electrode means permanently, mechanically, and electrically interconnected with said piezoelectric means and electrically isolated from said head and said first electrode means, such that said electrode means and said piezoelectric means cooperate to form an ultrasonic transducer; and a second generally flat surface formed on said shank at a location remote from said one longitudinal end of said shank, said second flat surface being generally coplanar with said first flat surface and spaced a predetermined distance therefrom. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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21. A fastener adapted for measuring longitudinal strain in the fastener, said fastener comprising:
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a shank having a longitudinal axis and a predetermined longitudinal length, said shank being adapted to be subjected to longitudinal strain along said longitudinal axis; a head formed at one extreme and of said shank said fastener having a generally flat surface disposed on said head normal to said longitudinal axis; first electrode means permanently, mechanically, electrically, and acoustically interconnected with said head; piezoelectric film means permanently, mechanically, and electrically interconnected with said first electrode means; and second electrode means permanently, mechanically, and electrically interconnected with said piezoelectric means and electrically isolated from said head and said first electrode means; such that said electrode and said piezoelectric means cooperate to form an ultrasonic transducer. - View Dependent Claims (22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40)
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41. A fastener adapted for measuring longitudinal strain in the fastener, said fastener comprises:
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a shank having a longitudinal axis and a predetermined longitudinal length, said shank being adapted to be subjected to longitudinal strain along said longitudinal axis; a head formed a one extreme and of said shank, said fastener having a generally flat surface disposed on said head normal to said longitudinal axis; a first electrode means permanently, mechanically, electrically, and acoustically interconnected with said head by means of an adhesive; a thin piezoelectric film disk permanently, mechanically, and electrically interconnected with said first electrode means; second electrode means permanently, mechanically, and electrically interconnected with said piezoelectric film disk and electrically isolated from said head and said first electrode means, such that said electrode means and said piezoelectric film disk cooperated to form an ultrasonic transducer, said first and second electrode means comprising metallic films disposed on opposite faces of said piezoelectric film disk. - View Dependent Claims (42, 43, 44, 45, 46, 47, 48, 49, 50)
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Specification