Abstract: A gas compressor includes a compression chamber, an outlet valve, and a shuttle valve which disables the outlet valve when it is connected to an atmospheric pressure relief chamber in idle operation. A throttle line circumventing the shuttle valve is provided which permits by-passed flow between the compression chamber and the atmospheric pressure relief chamber in idle operation, thereby preventing deposits and moisture condensation in the downstream flow path to the pressure relief chamber due to the disabling of the outlet valve, which might otherwise lead to possible operational malfunctions. Compressed-air systems employed in the automotive industry represent an important area of application for the invention.

Abstract: A gas compressor for vehicle braking systems controlled by compressed air can be operated under load or in idle operation. In idle operation, no compressed air is produced. In operation under load, the gas compressor produces compressed air as required by the pressure medium installation. During prolonged operation of the gas compressor at a relatively high operating speed, for example, during travel on super-highways, the power consumption can be decreased and thereby also the production amount of the gas compressor, without having to switch the gas compressor over into idle operation. A clearance volume of less volume than the nominal volume of the gas compressor is provided which can be connected via a valve to the compression chamber of the gas compressor, thereby making it possible to enlarge the compression volume. In addition, a process for the control of the auxiliary valve takes into account different operating magnitudes of the gas compressor and other elements of the vehicle.

Abstract: An installation for the production of pressure has three operating states corresponding to a delivery operation, an idle operation, and a partial delivery operation. The installation contains at least two compression chambers in at least one compressor, each chamber being assigned at least one switchable inlet valve. In the delivery operation, the switchable inlet valves act as check-valves that allow pressure medium to flow into their respective compression chambers. Each compression chamber also contains at least one outlet check valve through which compressed pressure medium flows out to a pressure consuming system in the delivery operation. Each switchable inlet valve also has an idling position that allows pressure medium to flow into the applicable compression chamber and back out again without being substantially compressed. In the idle operation of the installation, each switchable inlet valve switches to its idling position.

Abstract: A compressor with a cylinder head (33, 29) comprises a lower cylinder head section (33) and an upper cylinder head section (29) connected to each other. A seal (12) is provided between the faces of the lower cylinder head section (33) and the upper cylinder head section (29) facing each other. A suction space (31, 25) and a pressure space (10, 17) as well as a suction valve (32, 4) and a pressure valve (5, 7) are installed in the cylinder head (33, 29). A compression space (3) of the compressor is connected by the suction valve (32, 4) to the suction space (31, 25), and by the pressure valve (5, 7) to the pressure space (10, 17). The suction space (31, 25) is also connected by a suction connection (71) to the atmosphere, and the pressure space (10, 17) is connected to a consumer by a pressure connection (18) to a source of pressure.

Abstract: The inventive device controls the trailing axle of a vehicle having at least two rear axles, wherein at least one rear axle is a driving axle. Pressure fluid chambers, mounted on both the driving and trailing axles, support the vehicle structure. Their pressure is varied to raise or lower the vehicle structure depending on the vehicle load and road conditions. The inventive device further comprises a first valve arrangement and a second valve arrangement. The first valve arrangement selectively connects the pressure fluid chambers of the driving axle to a compressed-air supply, to a pressure fluid sink, or isolates them. The first valve arrangement has a first and a second valve. The first valve is a 3/2-position valve actuated by a first solenoid. The second valve of the first valve arrangement is a 2/2-position valve actuated by a second solenoid. The second valve arrangement is a 3-position valve actuated by a third solenoid.

Abstract: An apparatus for the generation of compressed air is disclosed, where the supply of air from the compressor (1) to the user (6) is interrupted in case of preset user-side pressure. This apparatus prevents a freezing in case of low ambient temperatures in the pressure lines in which condensed water has formed. A temperature sensitive switching device (14, 29) responds to the actual ambient temperature. The switching device (14) does not stop the compressor (1) in case of a preset user-side pressure and in case of a falling below of a preset ambient temperature. The compressor (1) carries then the warmed-up air through a region of the device before discharging it into the surrounding atmosphere. The device is particularly suited for compressed-air generation plants in motor vehicles which are adapted to be used in cases of low ambient temperatures.

Abstract: A level control system for motor vehicles having pneumatic springs which function in accordance with the vehicle load. A specified distance is normally maintained between the vehicle body the vehicle axle. This distance is maintained by charging or discharging the pneumatic springs. The level control system includes an air dryer and a pneumatic relay type of controllable discharge valve having a relatively large cross-sectional port by which the air dryer is connected to the atmosphere. The discharge valve operates against a spring return force. The magnitude of the spring return force corresponds to a preselected minimum pneumatic spring pressure. The system counteracts an icing action of the discharge valve and prevents an unintentional and complete discharging of the pneumatic springs.

Abstract: A level control arrangement for motor vehicles having air springs which are functionally responsive to the vehicle load. A predetermined distance of the vehicle frame from the vehicle axis can be maintained by charging or discharging the air springs. The control arrangement includes a safety valve which can be controlled by the pressure in the air springs. When the vehicle is overloaded, or if a malfunction occurs in the control apparatus of the level control arrangement, the safety valve limits the pressure in the air springs to a preselected maximum safe pressure.