Abstract: A self-closing connector in accordance with the invention comprises at least one duct, at least one end orifice, and a sliding valve plate for closing said orifice, the connector is essentially characterized by the fact that said orifice (11, 28, 29, 32) is delimited by at least two lines of sealing (17, 26) disposed on respective closed curves and each belonging to a respective one of two cylindrical surfaces having generator lines extending in the same direction, and in that the sliding valve plate 12 has at least two sealing (12) surfaces belonging to said cylindrical surfaces respectively, with the projection of the section areas of the valve plate which co-operate with respective one of said two sealing lines on a plane P perpendicular to said generator lines having values equal to S'.sub.1 and S'.sub.2. Said section areas are chosen to be equal. This enables the effects of externally-applied pressure to cancel.

Abstract: A process and an apparatus for the recovery of energy, in the form of electricity, from a engine on a test bench. The apparatus includes, in particular, a brake coupled to the engine being tested, and an asynchronous motor/generator or dynamo connected to the distribution network to be supplied, a rotational velocity sensing apparatus provided at the output shaft of the engine, and a torque sensing apparatus. The apparatus also includes a coupler to achieve a selectively variable coupling between the brake and the asynchronous motor/generator or dynamo, while an electronic control and operating mechanism or controller, such as a computer, is provided to receive the signals from the velocity sensing apparatus and the torque sensing apparatus so as to assure the desired control of the velocity and/or of the torque, and to control the placement in operation or out of operation of the brake and/or the coupler.The invention likewise relates to a process for the recovery of energy utilizing such an apparatus.

Abstract: An apparatus for protecting a pressure differential sensor from exceeding a maximum allowable pressure differential. The apparatus has a housing which has a low-pressure chamber and a high-pressure chamber. A pressure-sensitive member separates the high-pressure chamber and the low-pressure chamber from one another. A blocking member is provided for blocking the entrance of fluid into the high-pressure chamber in response to the pressure-sensitive member sensing an initial differential pressure between the high-pressure chamber and the low-pressure chamber which exceeds the maximum allowable differential pressure. There may also be provided equilibration structure for creating a hysteresis loop as to the magnitude of the pressure differential between the high-pressure chamber and the low-pressure chamber.