Abstract: Strain gauge transducers (15) are fitted to the leading and trailing faces of a vehicle axle between each wheel (14) and the adjacent suspension (13). They have strain gauges (6, 7, 8, 9) in balanced bridge formation and their orientation is such that their outputs can be combined in one circuit (16, 17, 18) to produce an indication of axle loading and in another circuit to produce an indication (26) of torsion, these signals not being influenced by irrelevant strains. The information from the transducers can be combined to indicate individual axle loading, and total loading, and the torsional signal can be used in an anti-skid braking system.

Abstract: Strain gauge transducers (5,6,7,8,9) are fitted in pairs to a vehicle axle (2), generally between each wheel (3) and the adjacent suspension (4). They have strain gauges in balanced bridge formation and their orientation is such that their outputs can be combined to produce an indication of various loads, eliminating the influence of irrelevant strains. In one pairing, one transducer is on top of the axle while the other is on a front or rear face. In another pairing both transducers are on top of the axle at different longitudinal positions.

Abstract: A strain transducer is adapted to measure strain at a chosen depth below the surface of a workpiece, such as at the neutral axis of a draft bar. The transducer has a hollow cylindrical plug (6) projecting from a co-axial shoulder (7) of slightly larger diameter, the distal end of the plug being force fitted with a disc-like diaphragm (9) on which strain gauges (10) are mounted. These are on the inside face, and connections (11) extend up inside the plug to encapsulated electronic circuitry at the proximal end. The workpiece is bored (3) to an extent greater than the chosen depth and then counterbored (4) to match the plug and shoulder, and the transducer is inserted with an interference fit.

Abstract: Strain gauge transducers (15) are fitted to the leading and trailing faces of a vehicle axle between each wheel (14) and the adjacent suspension (13). They have strain gauges (6, 7, 8, 9) in balanced bridge formation and their orientation is such that their outputs can be combined in one circuit (16, 17, 18) to produce an indication of axle loading and in another circuit to produce an indication (26) of torsion, these signals not being influenced by irrelevant strains. The information from the transducers can be combined to indicate individual axle loading, and total loading, and the torsional signal can be used in an anti-skid braking system.

Abstract: A strain transducer of the kind in which a plug is inset into a workpiece surface requires an accurate interface fit with a drilled hole. One method proposes an oversize hole (12) which first receives an annular insert (14) in whose aperture (15) the transducer plug is a precision fit. The outer cylindrical surface of the insert has axially parallel serrations (16) which bite into the sides of the hole. Another method also has an oversize hole (22) whose mouth is constricted by a cylindrical punch (25) around a precision mandrel (24) which is then replaced by the transducer plug (28). Serrations (35) may alternatively be provided directly on the transducer plug (32), which can then be driven into a drilled hole (36) of only approximate accuracy.