Abstract: A loading assembly for applying a load to a test specimen includes a container having a volume of compressible fluid for providing a spring. A cylinder having a bore operably connected to the container. A piston is slidable in the bore and is operably coupleable to the test specimen. A valve fluidly coupled to the bore selectively provides fluid to the bore to displace the piston. A controller controls the valve to cause nonresonant displacement of the piston.

Abstract: A loading assembly that permits a lateral force to be applied parallel to an axis of a vehicle spindle includes a support frame and a wheel adapter housing mounted to the vehicle spindle. A loading member is pivotally joined to the support frame at a position spaced apart from the wheel adapter housing on the axis of the spindle. A plurality of spaced apart struts connects the loading member to the wheel adapter housing. An actuator applies a selected force to the loading member, which is transferred as a lateral force to the vehicle spindle. In a first embodiment, an adjustable coupling is provided between the actuator and the loading member to emulate a rolling radius of a tire assembly mounted to the vehicle spindle. In a second embodiment, a second loading member is operably connected to the first-mentioned loading member. A second actuator applies a force to the second loading member to apply a selected moment to the vehicle spindle.

Abstract: A sensing apparatus for sensing at least two physical quantities is disclosed. The sensing apparatus includes a first transducer that provides a first output signal proportional to a first measured quantity represented and a second transducer that provides a second output signal proportional to a second measured quantity. An excitation regulator device is connected to the first transducer and the second transducer. The excitation regulator device provides an excitation signal to the second transducer so that the second transducer output signal is referenced to the first transducer output signal in order to obtain a resultant output signal which is a combination of the first and second output signals.

Abstract: A tensile test controller has both load and stroke control circuits that are coupled together to permit tensile testing a specimen while controlling the load on the specimen, and when the specimen yields, for safely and smoothly switching to stroke control to complete the test and break the specimen. The controller has circuits which provide control over the velocity of the actuator as the specimen yields, and to prevent the specimen from being placed into compression, and also to sense the plastic specimen deformation a desired amount after it has yielded, but before the stroke control function is activated. Simplified supervisory gates are used to insure that the appropriate signal is controlling the test.

Abstract: A test system for testing axles and wheel spindles directly in place on vehicles such as automobiles, which simplifies the loading to obtain the necessary information for testing axles and spindles using two sets of actuators, each set comprising a pair of actuators each operating to control loads on the spindle along two different orthogonal components of normal movement of the vehicle. The actuator arrangement saves space, permits testing without removing automotive sheet metal and simplifies the compensation factors necessary for controlling such systems.

Abstract: A linear spring system using pneumatic cylinders arranged to give a substantially linear force versus displacement curve across a wide range of displacement and which is capable of providing large forces with mechanism.

Abstract: A pressure balance bearing providing a hydrostatic bearing film, which is connected to maintain a load or device in a constant position in relation to a reference or support surface. Several support bearings are plumbed together so that there may be cross flow between the bearings. An external control valve is mounted on the member and senses the relative position of the object. The valve in turn adjusts the flow of oil into the bearings as a function of changes of relative position of the object and reference or support surface. As shown, a large mass is supported on the pressure balance bearings and is capable of bilateral movement. The mass is supported on a plurality of bearings using three control valves arranged in a tripod configuration.

Abstract: A pressure balanced hydrostatic slip bearing as shown for use in guiding and restraining a test table which is shaken in longitudinal direction to vibrate or shake test objects, and also which may be shaken in vertical direction. The slip bearing controls lateral position of the table during operation. A second slip bearing applies a constant compressive preload force to one side of the table and the other pressure balanced bearing is a constant displacement bearing positioned on an opposite side of the table to react lateral forces which may be imposed on the table during operation.