Abstract: An elongated structure is provided including a pair of opposite end transverse end members and a plurality of laterally spaced apart and longitudinally extending bar members extending between and supported atop corresponding longitudinally spaced portions of the transverse end members. Mid-length portions of the transverse end members include upwardly and outwardly inclined shank portions over which the lower ends of upwardly and outwardly inclined bridging members are telescopingly engaged and each bridging member includes a pair of upwardly convergent bracing members whose upper ends are secured to the bridging members and whose lower ends are anchored relative to the opposite ends of the corresponding transverse member.

Abstract: A machine is disclosed for applying lengthwise tension to a length of pipe, such as a joint of pipe used in an oil well drill string, for example, for the purpose of testing the pipe for tensile strength. The machine includes gripping assemblies for holding opposite ends of the pipe in respective parts of the machine which are urged apart to apply tension to the pipe. Each gripping assembly includes a rotary mandrel which is threaded onto a sub secured to the respective pipe end, and a header rotatably mounting the mandrel. The header includes a plate providing restraint for the mandrel precluding its expulsion from the machine in the event of a pipe failure during the application of tension thereto. A rotary drive is provided for each mandrel for threading the mandrel onto and off the respective sub.

Abstract: The signal output of a pressure transducer, measuring the increasing tensile load above a minimum level on a test specimen, is differentiated to produce an analog slope signal compared with an adjusted sensitivity voltage to generate a reset signal when the elastic limit of the specimen is exceeded. Through digital gate logic enabled above a minimum tensile load, the reset signal terminates loading of the specimen to prevent destruction thereof.