Strain sensorextensiometer
First Claim
1. A strain measuring instrument with electrical output, comprising two end sections through which the instrument can be attached to a structure and a mid-section including a beam arranged substantially perpendicular to the instrument axis and mechanically connected to the end sections through two pairs of symmetrically arranged but unequally spaced flexible bridges and carrying at least two strain responsive resistive elements, said end sections and beam being integrally formed by a solid metal bar having a generally rectangular cross section.
4 Assignments
0 Petitions
Reexamination
Accused Products
Abstract
A strain sensor or extensiometer with electrical output designed to measure relative displacements between two axially spaced points on a stressed structure comprising an elongated body with two end sections and a centrally located flexible beam extending in a direction perpendicular to the longitudinal axis of the sensor body. Relative displacements of the end sections generate two opposing symmetrical torques at the ends of the beam. These torques or bending moments are impressed onto the beam through two sets of flexible bridges which are symmetrically located but unequally spaced on opposite sides of the beam. These two torques or couples cause the beam to bend evenly over its entire length. Resistance strain gages bonded to both sides of the beam at its center measure this bending.
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Citations
11 Claims
- 1. A strain measuring instrument with electrical output, comprising two end sections through which the instrument can be attached to a structure and a mid-section including a beam arranged substantially perpendicular to the instrument axis and mechanically connected to the end sections through two pairs of symmetrically arranged but unequally spaced flexible bridges and carrying at least two strain responsive resistive elements, said end sections and beam being integrally formed by a solid metal bar having a generally rectangular cross section.
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10. A strain measuring instrument comprising a beam having opposite ends, and a neutral axis of deflection along its length, force transmitting means connected to the opposite ends of the beam for producing oppositely directed couples on the ends so that the beam assumes a uniform curvature upon application of the forces, transducer means on opposite sides of the beam midway between said force transmitting means for sensing strain within said beam when deflected, means for rigidly connecting said force transmitting means to an object, and compensating means integrally attached to one of said end sections, said compensating means being operatively connected to said transducer means for generating an externally accessible output corresponding to the deflection of said beam such that the external operating characteristics of a variety of beams and transducer means having variable operating characteristics may be standardized.
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11. A strain measuring instrument with electrical output, comprising two end sections through which the instrument can be attached to a structure and a mid-section including a beam carrying at least two strain responsive resistive elements, said beam being arranged substantially perpendicular to the instrument axis and mechanically connected to the end sections through two pairs of symmetrically arranged but unequally spaced flexible bridges, said beam further including a pair of notches formed in said beam on opposite sides of each bridge where said bridges intersect said beam thereby forming flexure pivots between said beam and bridges and placing the centers of said pivots toward the neutral axis of said beam.
Specification