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.

Abstract: A testing apparatus for cyclically loading specimens of a known configuration to determine properties of materials from propagation or growth of a crack through the specimen including means to provide a direct output which is a function of crack length derived from measurements of the load and the displacement of the specimen.

Abstract: A prefeeder drive for a sheet of material positioned on the input side of a standard incremental type sheet feeder for a forming press and which has drive rolls that move a sheet of material through a lubrication bath and toward the press. The sheet is driven to form an upright or overhead loop prior to entry of the sheet into the main, incremental feeder. The drive comprises a pair of rolls which are driven in response to a feedback control system sensing the size of the overhead loop so that the loop size is maintained within a desired range to insure satisfactory feeding of the sheet material into the main feeder and thence into the press. The overhead or free standing loop substantially reduces the inertia of the material that the main feeder has to overcome when feeding an increment of sheet stock into the press, and thus makes the feeding of the material more reliable with less likelihood of misfeeds.

Abstract: A reciprocating sheet feeder for feeding sheet material into a press, such as a deep draw cupping press. The sheet feeder comprises a rocking or pivoting framework that has gripper means thereon for gripping the edges of the sheet to be fed and when the frame is rocked about its pivot axis, moving a length of the sheet into the press and then releasing the sheet prior to a return stroke for the rocking feeder.The grips of the rocking feeder thus reciprocate during use. The feeder is used in combination with edge guides that are positioned ahead of the grips with respect to the direction of movement of the sheet so that the sheet is primarily guided while under tension. The pivoting frame is made so that it does not have substantial strength in torsion or in lateral directions of the sheet, so that the sheet essentially guides the frame during the feeding stroke to avoid buckling or misguiding the sheet. The framework does have rigidity needed for moving the sheet in its longitudinal direction.

Abstract: A support for use with diametral and other types of extensometers to support the weight of the extensometer and also permit the extensometer to move with the specimen in its translational axes without substantial restraint, that is, up, down and in all directions sideways. At the same time the support provides restraint or stiffness in all three axes of rotation of the extensometer.