US 5,174,159 A · Linear displacement and strain measuring apparatus

Abstract

Linear displacement and strain measuring apparatus includes a linearly movable element, an emitter disposed on the movable element to move as the element is moved, for developing predetermined paterns of electric fields which vary linearly on the emitter in the direction of movement of the element, and a detector disposed in close proximity to the emitter adjacent the path in which the emitter moves to detect variations in the electric field patterns as the emitter is moved, for producing output signals representing variation in the electric field patterns and thus the linear displacement of the movable element relative to the detector. By attaching the movable element and the detector to spaced apart locations on a specimen, strain in the specimen can be measured.

Claims40

Dependent claims

Linear displacement measuring apparatus comprising

a linearly moveable element whose linear displacement is to be measured,
emitter means disposed on the moveable element to move as the element is moved, for developing predetermined patterns of electric fields which vary linearly on the emitter means in the direction of movement of the element, and
detector means disposed in close proximity to the emitter means adjacent the path in which the emitter means moves to detect variation in the electric field patterns as the emitter means is moved, for producing output signals representing variations in the electric field patterns and thus the linear displacement of the moveable element.

A uniaxial strain transducer comprising

a frame attachable to an object in which strain is to be measured,
an elongate element joined at one end to the frame and moveable in a linear direction relative thereto, said element being attachable at the other end thereof to the object,
emitter means disposed on the elongate element to move as the element is moved, and including at least one linear track extending in the direction of movement of the emitter means for developing predetermined patterns of electric fields which vary along the length of the track,
detector means disposed on the frame in close proximity to the emitter means adjacent the path of movement of the track for detecting variations in the electric field patterns as the track moves relative to the detector means and for producing output signals representing such variations and thus the amount of movement of the emitter means relative to the detector means.

1 more element

Dependencies are inferred from the claim text.

Linear displacement and strain measuring apparatus

Life of this patent

Linear displacement and strain measuring apparatus

Life of this patent

Abstract

Claims40