Abstract: Automotive leaf springs are produced from low-hardenability and specified hardenability steel, with identical and different length, width and thickness and constant or variable cross section profile, that are subjected to through-surface hardening and low tempering. The ideal critical diameter of hardening, carbon content and hardened layer depth depend on the thickness of constant cross section profile leaf and maximum and minimum thicknesses of variable cross section profile leafs. Adherence to the optimum correlations of parameters indicated make it possible to produce leaf springs with the best mechanical properties and longevity.

Abstract: A method of case hardening toothed gearing using low (LH) or specified hardness (SH) steel and using through surface hardening (TSH) in order to create a described case hardening pattern which increases the fatigue strength of the gear tooth.

Abstract: Automotive leaf springs are produced from low-hardenability and specified hardenability steel, with identical and different length, width and thickness and constant or variable cross section profile, that are subjected to through-surface hardening and low tempering. The ideal critical diameter of hardening, carbon content and hardened layer depth depend on the thickness of constant cross section profile leaf and maximum and minimum thicknesses of variable cross section profile leafs. Adherence to the optimum correlations of parameters indicated make it possible to produce leaf springs with the best mechanical properties and longevity.

Abstract: A method of case hardening toothed gearing using low (LH) or specified hardness (SH) steel and using through surface hardening (TSH) in order to create a described case hardening pattern which increases the fatigue strength of the gear tooth.

Abstract: Automotive leaf springs are produced from low-hardenability and specified hardenability steel, with identical and different length, width and thickness and constant or variable cross section profile, that are subjected to through-surface hardening and low tempering. The ideal critical diameter of hardening, carbon content and hardened layer depth depend on the thickness of constant cross section profile leaf and maximum and minimum thicknesses of variable cross section profile leafs. Adherence to the optimum correlations of parameters indicated make it possible to produce leaf springs with the highest mechanical properties and longevity.

Abstract: A method for making pipe joints on successive pipe sections introduced into an oil well as assembled into a pipeline in which the joints are substantially of the same dimensions as the pipe sections to allow for subsequent plastic expansion of the sections. In each joint, a female pipe end is tapered on the inside and an adjacent male end is tapered on the outside preferably with a complementary self locking taper which also has an interference fit. The female pipe end is heated to be expanded sufficiently to be assembled onto the male end and thereafter cooled to grip the male end in a leakproof manner. For larger pipe sizes, the tapered shapes have features which interlock in a leakproof manner when engaged after assembly of the pipe ends. The tapered shapes preferably are formed by a reversibly positioned forming tool which is alternately engaged with male and female pipe ends to ensure perfectly matching shapes.

Abstract: A method for making pipe joints on successive pipe sections introduced into an oil well as assembled into a pipeline in which the joints are substantially of the same dimensions as the pipe sections to allow for subsequent plastic expansion of the sections. In each joint, a female pipe end is tapered on the inside and an adjacent male end is tapered on the outside preferably with a complementary self locking taper which also has an interference fit. The female pipe end is heated to be expanded sufficiently to be assembled onto the male end and thereafter cooled to grip the male end in a leakproof manner. For larger pipe sizes, the tapered shapes have features which interlock in a leakproof manner when engaged after assembly of the pipe ends. The tapered shapes preferably are formed by a reversibly positioned forming tool which is alternately engaged with male and female pipe ends to ensure perfectly matching shapes.

Abstract: Apparatus is disclosed for detecting minute leaks in wheel rims, including a bell jar cover lowered over a rim previously placed in position on a support member, engagement of surfaces on the cover and support member with the tire bead flanges of the wheel rim creating a separate hermetically sealed interior and exterior test chamber, each defined in part by the periphery of the wheel rim. These testing chambers are first evacuated, and the exterior chamber then pressurized with a gas composed at least in part of a trace gas, while the interior chamber is placed at or below atmopsheric pressure. A scavenging gas flow is initiated through the interior chamber after a brief delay, which flow is collected and directed to a trace gas sensor to detect the presence of trace gas in the interior chamber resulting from leakage through the wheel rim. In order to eliminate residual trace gas, each test chamber is evacuated and purged with air flow prior to opening of the housing and removal of the wheel rim tested.

Abstract: A method and apparatus are disclosed for automatically compensating for the effects of variations in ambient trace gas levels or other causes of drift in trace gas leak detection testing, by generating a stored reference signal corresponding to the trace gas sensor output signal, freezing the reference signal at the beginning of each test and summing the output signal with the frozen reference signal to create a compensated output signal which is then compared with a preset threshold signal to trigger a reject during a given test. The uncompensated output signal is also continuously compared with a preset signal value and the test disabled if the output signal exceeds the preset signal at the beginning of each test.

Abstract: A method and fixture for leak detection testing of automotive fuel tanks and the like is disclosed. Two separable members are movable together to form a housing having an internal cavity shaped to receive tanks to be tested, with a sufficient clearance space to accommodate dimensional variations in the tanks to be tested. Each housing member is generally bowl-shaped with a relatively thin-walled, semi-rigid domed central portion, which with the members brought together defines a test cavity receiving the tank proper. Each member also has a relatively rigid peripheral rim supported in a frame. During testing, a tank is positioned within the test cavity and the tank interior pressurized with a trace gas mixture. The space between the housing and the tank is thereafter evacuated, causing the ribbed interior of the less rigid central portions of the housing members to move into contact with the tank exterior, preventing the high differential pressure from overexpanding the tank to cause damage.

Abstract: A method of compensating for temperature variations in testing part cavities for leaks by placing a fluid pressure source in communication with the cavity and measuring the flow rate to the cavity to determine the rate of any leakage. The method establishes a temperature compensation function by measuring the shift in flow rates resulting from changes in temperature of a sample test part, which temperature compensation function allows correction of the flow rates during subsequent testing according to the sensed temperature of the test part. Flow rates are measured at two differing temperatures to determine the temperature compensation function by linear regression, since the flow rate shift with temperature varies substantially linearly.

Abstract: An improved method of measuring leak rates by placing a source of fluid pressure in communication with a cavity being tested, and measuring the flow rate to the cavity after a predetermined time to determine the leak rate from the cavity. The improved method achieves a determination of the leak rate in a shorter time than that required to establish steady state flow conditions between the pressure source and the test piece cavity. The improved method measures the flow rate to the test piece cavity at a much earlier time after pressurization of the cavity than normally required to establish such steady state conditions, and applies a previously generated calibration function based on a linear correspondence between the measured flow rates and the steady state flow rates.