TORQUE SENSING DEVICE

A torque sensing device has a torque transmitting member with ends which are relatively rotatable around a member axis in response to an applied torque. Lost motion components rotating with the member ends have portions compactly extending along the member axis to engage the other component to limit such rotation after a predetermined degree of relative rotation has occurred. Two ferromagnetic elements rotating with the respective lost motion components have portions which extend along the member axis into interleaved relation with corresponding portions of the other element to form spaced pairs of respective element portions at each of two sides of a plane which extends transversely across the member axis. The elements respond to relative rotation of the torque transmitting member ends to proportionally increase the spacing in the pairs of element portions at one side of the noted plane and to decrease the spacing in the pairs of element portions at an opposite side of the plane. An exciting coil surrounding the elements induces magnetic leakage flux at the spacing of the pairs of element portions representative of the degree of spacing and a pair of sensing coils disposed around the elements are coupled to that magnetic leakage flux at respective sides of the noted plane. The sensing coils are differentially connected to provide an output signal corresponding to the applied torque.