Patent ID: 6389910
Filing Date: 2002-05-21
Classification: B62D,G01L

Abstract:
A torque transducer comprising a rotating shaft at least partially surrounded by a fixed housing, an axis of rotation of the shaft fixed with respect to the housing, the shaft comprising first and second torque input members connected by a torsionally compliant coupling, the coupling enabling angular deflection of the first torque input member relative to the second torque input member as a function of a magnitude of the torque in the shaft, the transducer comprising at least one electro-magnetic radiation (EMR) source and at least one array of EMR sensitive detectors, a first grating element attached to the first toque input member and a second grating element attached to the second torque input member, the first and second grating elements each comprising a grating zone, each grating zone comprising alternating regions of high and low transmissibility to the EMR, wherein only one grating zone of one grating element resides in a transmission path communicating EMR from any source to any array, a pattern is produced by incident EMR on each of the at least one array resulting from the alternating regions of high and low transmissibility of the grating zone residing in the at least one transmission path to that array, a pattern on the at least one array is processed by a processor to derive a relative angular deflection of the first and second torque input members and hence provide a measure of the magnitude of the torque in the shaft.