Patent ID: 9347764
Filing Date: 2016-05-24
CPC Classification: G01B,G01D

Claim Text:
1. A sensor assembly for determining a location of a structure that is translated along a movement axis, the sensor assembly comprising: a sensor mount; a first sensor coupled to the sensor mount, the first sensor being an eddy current sensor having a first X-axis, a first Y-axis and a first Z-axis that are orthogonal to one another, the first X-axis being disposed parallel to the movement axis, the first sensor comprising a first coil that is wound helically around the first Z-axis such that a first dimension across the first coil along the first Y-axis is larger than a second dimension across the first coil along the first X-axis; a second sensor coupled to the sensor mount, the second sensor being an eddy current sensor having a second X-axis, a second Y-axis, and a second Z-axis that are orthogonal to one another, the second X-axis being parallel to the first X-axis, the second Z-axis being parallel to the first Z-axis, the second sensor comprising a second coil that is wound helically around the second Z-axis such that a third dimension across the second coil along the second Y-axis is larger than a fourth dimension across the second coil along the second X-axis; a first target that is coupled to the structure for movement therewith, the first target being formed of an electrically conductive material and being configured to interact with the first sensor to produce a first sensor signal that has a first magnitude that varies proportionally with movement of the first target along the first X-axis; and a second target that is coupled to the structure for movement therewith, the second target being formed of an electrically conductive material and being configured to interact with the second sensor to produce a second sensor signal that has a second magnitude that varies proportionally with movement of the second target along the second X-axis; wherein the first and second targets are configured so that coordinated movement of the first and second targets within predefined limits in a direction parallel to the first and second Z-axes as the structure is moved along the movement axis is detectable from the first and second sensor signals; and wherein the first and second targets further configured so that coordinated movement of the first and second targets within second predefined limits in a second direction parallel to the first and second Y-axes as the structure is moved along the movement axis is detectable from the first and second sensor signals; and wherein the sensor assembly is insensitive to relative movement within predefined limits between the structure to which the first and second sensor targets are mounted and the first and second sensors in a direction that is parallel to the Y-axes.