Abstract: A probe assembly is disclosed carrying a grid grating and an index grating adapted to generate a Moire pattern upon relative movement in either or both of two orthogonal directions in a common plane. The index and grid gratings are supported for precise orthogonal motion with respect to each other by means of a pair of grating support assemblies mounted so that the correct index and grid grating spacing and orientation are precisely maintained, including a cross-slide assembly provided to allow movement in a plane while maintaining the proper orientation between the grating assemblies.

Abstract: A two-axis Moire fringe displacement transducer is disclosed in which the scale grating is inscribed with a grid pattern consisting of two superimposed orthogonal optical line sets and the index grating is inscribed with at least two discrete optical grating patterns, each of the at least two grating patterns aligned with a respective grid grating set such as to generate Moire fringe patterns in a respective grating upon relative movement along each orthogonal direction.

Abstract: A load cell capable of measuring forces along three orthogonal axes as well as bending moments about each of these axes is disclosed which is of simple construction while being capable of measuring accurately a wide range of dynamic working loads. The load cell consists of a housing drivingly connected to a central hub member by means of a cross pattern formed by pairs of compliant cantilever bars, each bar slidable in the housing along its axis so as to not be capable of resisting transverse loads along respective orthogonal axes in the plane transverse to the load cell. Displacements of the hub relative to the housing are measured by four sets of LVDT transducers, each set measuring relative lateral movement parallel to each of the orthogonal axes on opposing points radially displaced from the central axis of the load cell. These displacements are used to generate signals corresponding to the force components along each of the orthogonal axes as well as bending moments about each of these axes.