Abstract: A simple, operationally reliable and not-overly-sensitive level control in a generally known form of self-pumping hydropneumatic spring leg or strut is of such a construction that a delayed adjust-down control action can be achieved when a control opening is opened upon reaching a certain level. For that purpose, a sleeve is fitted as or as part of a throttle arrangement between the control opening of a hollow pump rod and a suction valve arranged at the end of the pump rod, the sleeve allowing oil to flow with a delay from the high pressure chamber which controls the level, by way of the control opening of the pump rod to the pump rod bore, the bore communicating with a low pressure chamber from which oil is normally pumped to the high pressure chamber. By removing the throttling responsibility from the control opening, size restrictions on the control opening are removed, thus facilitating sizing the control opening so as to preclude clogging.

Abstract: A self-pumping, hydropneumatic, telescopic, spring damping device with internal level regulation, especially for automotive vehicles, includes an oil filled working chamber and a working piston with damping devices, the working piston rod being hollow and forming a pump chamber for a pump rod which automatically pumps oil from an oil reservoir into the working chamber. A control opening permits flow from the work chamber to the oil reservoir when the desired level is exceeded. A gas cushion in a gas spring chamber connected with the working chamber pressurizes the oil in the working chamber. The gas spring chamber includes a separating piston, and may be connected axially to the working chamber in the region of a flexible or elastic partition which supports the pump rod. The partition includes communicating passages. A pump suction tube communicates a pump rod cavity with the oil reservoir, and is yieldable with respect to movements of the flexible partition.

Abstract: A self pumping, level regulating apparatus for vehicles comprises at least one hydropneumatic, telescoping spring element, and a pumping and regulating element for pumping oil into the work chamber of the spring element as a function of the motion of an axle of the vehicle, to raise the level of oil in the work chamber, and hence the level of the vehicle and for moving oil out of the work chamber when a predetermined level is exceeded. In contrast to an arrangement where the telescoping spring element and the pumping and regulating element are integrated and disposed between relatively movable members, such as levers fixed to two associated swinging axle halves, only the pumping and regulating element is so disposed, and the telescoping spring element is separately disposed between the vehicle body and the wheel axle. A better distribution of force is thus achieved. Moreover, a single pumping and regulating element can serve a number of hydropneumatic spring elements.

Abstract: A self-pumping, hydropneumatic, telescopic, spring damping device with internal level regulation, especially for automotive vehicles, includes an oil filled working chamber and a working piston with damping devices, the working piston rod being hollow and forming a pump chamber for a pump rod which automatically pumps oil from an oil reservoir into the working chamber. A control opening permits flow from the work chamber to the oil reservoir when the desired oil level is exceeded. A gas cushion in a gas spring chamber connected with the working chamber pressurizes the oil in the working chamber. The gas spring chamber includes a separating piston and is connected axially to the working chamber in the region of a flexible or elastic partition which supports the pump rod. The partition includes communicating passages. A pump suction tube communicates a pump rod cavity with the oil reservoir, and is yieldable with respect to movements of the flexible partition.

Abstract: An apparatus for the tensioning and relaxing of a safety belt including an elongated housing, a tensioning piston, and a tie rod for connection with the safety belt and arranged for retraction relative to the housing in response to pressure on the tensioning piston as well as being arranged thereafter for extension relative to the housing with a delay in response to tensile stress on the safety belt. A hydraulic damping arrangement including a damping cylinder containing a liquid and damping piston coupled with the tensioning piston is provided for forming a telescopic arrangement such that after the tensioning piston effects the retraction of the tie rod and reaches an arrested retracted position thereof, the hydraulic damping arrangement enables damped extension of the tie rod relative to the housing by displacement of the damping piston which in turn displaces liquid in the damping cylinder in response to tensile stress on the safety belt.