Abstract: A method and apparatus for reducing the loading impact between a sealing element in a suction valve of a piston compressor with a valve stop, wherein the sealing element is forcibly opened using a control device shortly before attaining pressure balance between cylinder and suction chambers of the compressor.

Abstract: To influence the periodic stroke movement of the closing element of a valve, a control cylinder working on the closing element in the stroke direction is provided, which can be acted upon or released by a control element periodically with pressure medium. The control element is connected in the supply or discharge conduit of the pressure medium and can variably accelerate or slow its pressure formation or release and with it also the stroke movement of the closing element, at last gradually. Thus a partially or completely automatic control of compressor valves, for example, can be made possible in a simple manner.

Abstract: A plurality of concentric annular plates (1) are braced against a valve guard (2) by means of radially arranged spring-loaded bridges (5). The guided height (6) of the bridges (5) is at least equal to the maximum lifting height (7) of the annular plates (1) which abut against centering elements (8) of the bridges (5) and are guided by means of the bridges (5) relative to the valve guard (2) along the entire lift. A very simple guiding of the annular plates (1), which preferably impact against the valve guard (2) only via the bridges (5) and thus show a reduced tendency to sticking, is achieved particularly by constructing the annular plates (1) and/or bridges (5) from fiber-inforced plastic material.

Abstract: A valve lifter for compressor valves includes a carrier, and a plurality of fingers secured thereto, the fingers including a retaining element co-operating with the carrier so as to provide a positive fit. At least one retaining element incorporates a positioning element that established its position relative to the carrier, and a fixing element that snaps into position in the installation position on the carrier. It is preferred that the fingers be of long glass fiber reinforced polyamide, which permits a simple and secure connection of the fingers to the carrier that does not settle.

Abstract: A device for reducing pressure in a compressor when it is in the idling and shut-down mode, in the induction manifold of which there is an induction control valve that controls the passage through the induction manifold, is provided with a bypass line that incorporates a closeable relief valve. The device for reducing pressure incorporates a spring-loaded pressure keeper valve that can be adjusted to the desired pressure, and an additional second relief valve that is arranged in parallel to the first relief valve. This second relief valve is acted upon by the pressure immediately upstream of the compressor in the induction manifold, and opens an additional relief path as soon as this pressure exceeds a pro-determined level when the compressor is shut down. The two relief valves and the pressure keeper valve can be incorporated into a common housing.

Abstract: An induction regulator valve is incorporated in the induction manifold of a compressor to provide for infinitely variable regulation of the output from the rotary type compressor, in particular the screw-type compressor. The closing piece of the induction regulator valve can be adjusted by means of an actuator system. To improve this regulation performance of this system, in particular to reduce its sensitivity when the regulator valve is almost closed, the spring system is formed so that its stiffness varies along the length of its spring path, the stiffness of the spring system being smaller when the induction regulator valve is open than when it approaches the closed position of the closing piece of the induction regulator valve.

Abstract: A sealing ring (10) includes an outer sealing region (11) with a sealing edge (18) which rests in the installed state against the surface region to be sealed, and a holder region (12) which is situated within the sealing region (11). To prevent or render the pulling out of the sealing ring (10) from the corresponding groove-shaped recess (13) more difficult, the groove-shaped recess (13) includes at least one offset holding shoulder (16), and the holding region of the sealing ring (10) includes at least one corresponding holding edge (17), which in the installed state of the sealing ring (10) holds the sealing ring shape-lockingly like a barb.

Abstract: An intake control valve for a screw-type compressor is built into the intake line, which it alternatingly opens or closes. The intake control valve, designed as a double seat valve, has a locking body (17), to which are assigned two opposing valve seats, namely a return flow seat (7) and an intake seat (9). Upon starting the screw-type compressor, the locking body (17) is pulled onto the intake seat (9) by means of the resulting intake pressure. As soon as a specific operating pressure is reached, the locking body (17) is lifted from the intake seat (9) by means of the pressure medium by way of a control cylinder (10) with a control piston (11) and moved into an intermediate position between its two seats (7, 9), so that the screw-type compressor can totally transport.

Abstract: A power steering system is actuated by a controller which includes a Bowden cable having a core and a sheath. The core is connected directly mechanically to a control mechanism and the sheath is connected hydraulically to the control mechanism by a control valve and an operating cylinder. To balance a reaction of the control mechanism on the core and thus undesired steering movements of the power steering system, a brake unit is disposed between the core and the sheath of the Bowden cable to prevent relative movement between the two by means of friction.

Abstract: A power steering system (3) includes a controller (1) and a control mechanism (3), which can be operated by way of a Bowden cable (5) having a core (7) and a sheath (6). The core (7) is connected directly mechanically to the control mechanism (3), and the sheath (6) is connected hydraulically to the control mechanism (3) by way of a control valve (8) and an operating cylinder (9). To prevent oscillations in the closed control circuit of the power steering system, the sheath (6), or the control piston (15) of the control valve (8) connected thereto, is provided with a damping device (18) to dampen the axial movement of the control piston (15). The damping device provides hydraulic damping of the control piston (15).

Abstract: An automatic valve for use in compressors or an otherwise non-return valve has a valve seat with passage channels which are controlled by a shutter blade (16). The shutter blade (16) includes a lock element (27) with concentric rings (19) connected together by radial cross pieces (29). The lock element (27) is guided by flexible guides (26). To enlarge the passage cross section through the valve and to improve the flow conditions, the guides (26), clamped on their outer rim, are guided radially inwardly from the clamping point with an outer cross piece (30); then pass over in the shape of an arch (31) with a relatively large radius of curvature into at least one ring section (32), which extends in the circumferential direction, and is provided with an outwardly directed bend (33), and in turn passes over in an inwardly directed arch (34) with an equally large radius of curvature into an inner cross piece (35), which adjoins the lock element (37).

Abstract: To connect the cylinder pipe (1) of a hydraulic cylinder to a bottom (6), and a cover (8), the bottom (6) and cover (8) have groove-shaped recesses (16, 17), into which are pressed the ends (5, 7) of the cylinder pipe (1) under permanent deformation. To enable pressurization at high operating pressures, the region (25) of the inner end of the non-deformed cylinder pipe (1) is defined as a holding region (18, 19) and has a turned groove (26) which, in the deformed state of the cylinder pipe (1), reaches over the related inner edge (27) of the groove-shaped recesses (16, 17) with respect to the longitudinal stretch of the cylinder pipe (1).

Abstract: For a piezo valve (1) the sealable surface of the seat (13) of the controllable medium connection is so large that the pressure-induced closing force of the sealing region (14) of the bending element (4) that is generated in accordance with the medium pressure acting in the second switch position is greater than the elastically induced counterforce and smaller than the total of this counterforce and the piezo reset force acting upon application of a corresponding control voltage. Thus, both switch positions of the valve can also be held for a long period of time following pulsed voltage operation without any additional voltage application.

Abstract: A hydraulic actuating apparatus for opening and closing a movable cover (convertible top) of a vehicle includes a piston/cylinder device, a reversible, motor driven pump for supplying hydraulic fluid to the piston/cylinder device to cause it to open or close the vehicle cover, and an auxiliary manual pump for supplying hydraulic fluid to the piston/cylinder device in the event of failure of the reversible pump.

Abstract: The riveting sleeve (6) described is used to connect the component parts (3, 4, 5, 10, 11) of compressor valves (2). The riveting sleeve (6) passes through the valve parts (3, 4, 5, 10, 11) to be connected to one another and is provided with at least one radial groove (16, 22, 26) which starts from the inner or outer generated surface (17, 18) thereof and weakens the wall thickness of the riveting sleeve (6) in this area. On the other side of the generated surface (17, 18) the groove (16, 22, 26) is adjacent either to the wall of a valve part surrounding it or surrounded thereby, or it has opposite it a recess (19, 23, 27) in the valve part (3, 5, 25) adjacent to the riveting sleeve (6). By upsetting the riveting sleeve (6) by means of an applied axial force, the riveting sleeve (6) is deformed radially outwards or inwards in the manner of a bead, it being securely clamped in or on the adjacent valve part.

Abstract: A valve for a piston-type compressor includes a valve seating with throughflow channels, a closure piece for controlling these channels, a spacer and a spring means urging the closure piece against the valve seating and supported on an arrester which at the same time forms the limit stop for the closure piece. In order to anchor the valve parts on the valve seating before the installation of the valve, at least one sleeve serving as a transport securing means and as an assembly aid is provided, which is secured at one end on the valve seating or on the arrester, and the individual valve parts are pushed in the correct installation position onto the sleeve. The other end of the sleeve is widened. A tension screw passes through the sleeve in an axial direction. The sleeve can be rolled into an undercut annular groove of the valve seating and at the outer surface of the arrester end flush with the latter.

Abstract: A valve seat plate (1) having at least three individual plates (2, 3, 4) which lie upon one another and exhibits, on the one hand, continuous channels (5) for the medium to be controlled and defines, on the other hand, cavities (16) between the channels for the coolant, includes sleeves (8) that define the channels and are sealed with respect to the cavities and extend through the thickness of the valve seat plate.

Abstract: The valve, which is intended especially for compressors, comprises a valve seat (1) with passage channels (2), a catcher (3), and at least one sealing element (5), which is arranged in the intermediate space between the valve seat (1) and the catcher (3). The passage channels (2) of the valve seat (1) are controlled by sealing rings (10), which project into their assigned passage channel (2) with one part of their profile when the valve is closed. The sealing surfaces (13), against which the sealing rings (10) abut when the valve is closed, extend at oblique angles to the direction of the lifting movement of the sealing rings (10). To ensure that the valve is sealed even when the sealing rings (10) in their dimensions do not fit accurately with respect to the valve seat (1) and to its sealing surfaces (13), e.g.

Abstract: The compressor unit consists of a screw compressor (2) and a drive motor (1), which is connected for drive purposes to the screw compressor (2) by way of an engageable and disengageable clutch (3) and can be temporarily stopped in order to control the throughput of the screw compressor (2). To allow starting of the compressor unit without the drive motor (1) becoming thermally overloaded, the clutch inserted between the drive motor (1) and screw compressor (2) is in the form of a known centrifugal clutch (3), the driving clutch member (17) being connectable to the driven clutch member (18) by means of friction plates (23, 28). For automatic operation of the centrifugal clutch (3), a control chamber (21) is provided, the presser plate (36) of which is adjustable against the friction plates (23, 28) by means of centrifugal weights (34).

Abstract: A compressor plate valve has a valve seat, a valve guard and at least one valve plate which is mobile to-and-fro therebetween to control passage channels provided in the valve seat. To enable the compressor to be switched to idle running, a lifting device is provided for keeping the valve open. This comprises a seating plate which is disposed mobile between the valve seat and the valve plate in the direction of the lifting movement and has valve ports aligned with the passage channels in the valve seat and connection apertures corresponding with the passage apertures in the valve plate. The lifting force is applied to the seating plate by means of a control device.