Abstract: A hydraulic tensioner for a traction drive is provided having a spring-loaded piston (8) guided for longitudinal motion in a cylinder (6), in which tensioner, a piston motion causes an exchange of volume between a high pressure chamber (9) arranged in the cylinder (8) and a hollow space (4) which is partly filled with hydraulic medium, and, depending on a direction of motion of the piston (8), said exchange of volume can take place through a one-way valve (15), the tensioner further comprising a bellows seal (18) which is arranged between the piston (8) or the piston housing (10) at one end, and the outer housing (2) at a second end and follows the longitudinal motion of the piston (8) while bearing under pre-stress against the outer housing (2) and against the radially inward stepped piston housing (10).

Abstract: An apparatus (1) for changing the opening and closing times of gas exchange valves of an internal combustion engine has intercommunicating slide and freewheel means (15, 20). By means of these elements (15, 20), immediately upon starting the internal combustion engine, and adjusting piston (7) of the apparatus (1) is moved into its desired starting position and/or held there long enough for the apparatus (1) to be filled sufficiently with hydraulic fluid again. During the hydraulic-fluid-free state, the adjusting piston (7) is at the same time largely prevented from making any undesired oscillations.

Abstract: Apparatus for converting a rotational motion into an axial motion, includes a threaded spindle (9), a sleeve (10) in concentric surrounding relationship to the spindle at a spacing thereto, and a plurality of axis parallel rollers (1, 5) arranged in the spacing, with each of the rollers being provided with a circumferential profile and meshing with the threaded spindle (9). According to the invention, each roller (1, 5) is axially supported with both its end faces via rolling bodies (19) on housing plates (14, 15) which are arranged in fixed rotative engagement within the sleeve (10).

Abstract: A sealing arrangement for a direct-controlled cartridge valve in an insertion bore, which valve is arranged in a hydraulic system of a device for varying the valve timing of an internal combustion engine wherein to avoid leakages between the individual annular chambers (20, 21, 22) in the insertion bore (23) resulting from the radial clearance between the annular webs (8, 9, 10) of the cartridge (5) and the bore wall (24) of the insertion bore (23), the annular webs (8, 9, 10) on the outer peripheral surface (6) of the cartridge (5) are made with a smaller diameter than the insertion bore (23) and additionally comprise annular grooves (14, 15, 16) into which annular sealing elements (17, 18, 19) made of a shear-resistant material are inserted, and leakages between the sealing elements (17, 18, 19) and the cartridge (5), as also leakages between the sealing elements (17, 18, 19) and the bore wall (24) of the insertion bore (23) are sealed by a static radial force resulting from the pre-stress of the sealing el

Abstract: A device for varying the opening and closing times of gas exchange valves of an internal combustion engine, comprising a drive unit (2) which is in driving relationship with a crankshaft through a traction element and a driven unit (14) connected to an intake or exhaust camshaft, there being arranged within the device (1), a coupling element (18) by which a rotationally fixed, force-transmitting connection can be established between the drive unit (2) and the driven unit (14) when the pressure of the hydraulic medium falls below a level required for the displacement of the adjusting piston (9), the coupling element (18) being configured as a locking piston (19) which can be displaced on the one hand by hydraulic pressure and on the other hand by an auxiliary energy and comprises on an end face (26) a number of concentrically arranged extensions (27) which are associated to complementary recesses (35) of a locking ring (34) in the housing (6) to avoid noise generation on starting of the internal combustion eng

Abstract: A form of folded thermoplastic pipe is disclosed for use in repairing a pipeline. Also disclosed are methods and apparatuses especially for installing the thermoplastic pipe in an existing underground pipeline, such as a service lateral, having access from only one end and a bend along its length. The thermoplastic pipe is manufactured in folded form so as to have a folded memory, and spooled for storage in such form. The folded pipe is reheated to make it pliable for installation, and is pulled into the lateral from the access opening using a cable-and-pulley arrangement anchored temporarily at the intersection of lateral and main pipelines. When the folded pipe is installed in the lateral, it is rounded and cured in its rounded shape by passing steam under pressure through passages along the folds of the pipe while its leading end is restricted.

Abstract: A valve tappet actuated by a cam of an internal combustion engine comprises a cup (1) having a hollow cylindrical skirt (2) and a cup bottom (3) which closes the skirt (2) at one end. On an outer surface, the skirt (2) comprises a peripheral groove (4), and on an inner surface, at least one bead (5). Concentrically arranged within the cup (1) is an inner element (6) whose casing (9) bears against the bead (5, 21). A hydraulic valve clearance compensation element (10) is guided for axial displacement in the inner element (6). To simplify the manufacturing of this valve tappet, it is proposed that the cup (1) is hardened in a heat treatment process, and the inner element (5) is unhardened.

Abstract: A locking device for a device (1) for varying the valve timing of gas exchange valves of an internal combustion engine, said device (1) comprising an element (3) which is attached to a crankshaft of the internal combustion engine and is in driving relationship with the crankshaft through a traction element, said device further comprising an element (4) attached rotationally fast to the camshaft (2), there being arranged between the two said elements (3, 4), at least two pressure chambers (5, 6) connected to a pressure medium supply and a hydraulically actuatable adjusting element (7) through which a connection for transmitting force from the element (3) attached to the crankshaft to the element (4) attached to the camshaft is established, and through which the two said elements (3, 4) can be made to rotate or be fixed relative to each other within an adjusting range.

Abstract: A hydraulically controlled disconnect system for a friction clutch of motor vehicles is provided and is constructed as a slave cylinder which includes a pressure housing (2) which is arranged concentrically in relation to a gear box input shaft (3). A guiding sleeve is arranged radially apart from the pressure housing to create a circularly configured pressure chamber (9) in which a ring piston (7) is axially guided and movable. A reinforced seal (8a) on the pressure chamber side of the ring piston (7). The seal (8a) includes sealing lips (14, 15) which are arranged radially spread apart. In accordance with the invention, the reinforcement (18a) of the seal (8a) is held form-locking on the ring piston (7) with a degree of axial and radial freedom.

Abstract: A rocker arm or a finger lever (1) receives a valve clearance compensation element (4) in a reception bore (3). A cap (15) inserted into this reception bore (3) supports one end of an inner piston (7) of the valve clearance compensation element (4). This cap, through which on the one hand, the pressure medium is fed into an oil reservoir (8) and which, on the other hand, vents this oil reservoir (8) is fixed by an extension (17) in a complementary opening (18) of the rocker arm or the finger lever.

Abstract: A valve tappet actuated by a cam of an internal combustion engine comprises a cup (1) having a hollow cylindrical skirt (2) and a cup bottom (3) which closes the skirt (2) at one end. On an outer surface, the skirt (2) comprises a peripheral groove (4), and on an inner surface, at least one bead (5). Concentrically arranged within the cup (1) is an inner element (6) whose casing (9) bears against the bead (5, 21). A hydraulic valve clearance compensation element (10) is guided for axial displacement in the inner element (6). To simplify the manufacturing of this valve tappet, it is proposed that the cup (1) is hardened in a heat treatment process, and the inner element (5) is unhardened.

Abstract: A gearshift lever (3) is mounted on a ball-and-socket joint which is partially surrounded by a bearing shell (8) made of plastic whereby an economic mounting arrangement (2) which permits maintenance work and can prevent a transmission of vibrations to the gearshift lever (3) is achieved by the fact that the gearshift lever (3) is mounted through the bearing shell (8) on a ball (7) which is rigidly connected to an engine or gearbox casing (1), and the bearing shell (8) is connected to an outer ring (17) through damping rings (18, 19), the gearshift lever (3) being pivotally mounted on an outer peripheral surface of this outer ring through a hub (24).

Abstract: A rocker arm or finger lever (1) formed without machining (by a non-cutting shaping process) which has a U-shaped profile in cross section over almost its entire length which is open toward the top or the bottom, whereby the rocker arm or finger lever (1), in its end region in which it contacts a valve shaft end, is constructed double-walled. This rocker arm or finger lever (1) is distinguished in that the double-walled section or at least a strap (13) projecting over the longitudinal extension of the rocker arm or finger lever (1) is formed on an upper wall (10) which is bent under and lies between its two side walls (11, 12). A lever configured in this manner can be manufactured economically and has a good rigidity despite the reduced material used.

Abstract: A thin-walled inner bushing (1) comprising a raceway (5) which is provided with elastically yielding raceway convexities (2) which merge at one end into radially extending sections (7) which are connected to one another by a further, outer bushing (9) whereby play can be eliminated from the bearing even without the hitherto required intermediate rings of polymer material.

Abstract: A finger lever (1) is configured for the simultaneous loading of three identically operating gas exchange valves. To simplify the manufacture of a hydraulic medium supply of its hydraulic clearance compensation elements (4) resting on valve stem ends and to prevent unnecessary losses of hydraulic medium, the invention proposes the arrangement of only one central passage (12) in the finger lever (1) for supplying all the clearance compensation elements (4). This passage (12) extends near a central transverse plane of the finger lever (1) and opens into a cross-passage (10) in the form of a through-bore to the individual clearance compensation elements (4).

Abstract: An arrangement for controlling a device for changing the control times of gas exchange valves of an internal combustion engine is provided. The device includes a hydraulic pressure cylinder with an axially movable piston the setting motions of which are transformed into relative rotation of a drive part of the pressure cylinder connected to the crankshaft in relation to a drive part of the pressure cylinder connected to the camshaft. the hydraulic pressure cylinder is subdivided by the piston into two pressure chambers (3, 4), with each being provided with a pressure medium connection (5, 6) to which a hydraulic pump (7) is connected upstream and a pressure medium reservoir (8) is connected downstream, and whose pressure medium inflow or pressure medium outflow is controlled by a hydraulic valve arrangement controlled by a motor controller (9).

Abstract: The invention concerns a rolling bearing for a release device of a friction clutch. The rolling bearing (1a) includes a rotating outer bearing ring (12) and a rotationally fixed inner bearing ring (2). Rolling elements (15) are guided in an inner space (14) between the bearing rings which is sealed by a sealing element. The inner space (14) of the rolling bearing (1a) is sealed on one side of the rolling elements (15) by a sealing element (20) and on the other side of the rolling elements (15) by a retention element (7). The sealing element and the retention element are each rotationally fixed on one of the bearing rings, and free ends of the sealing element and the retention element extend up to the respective other bearing ring of the rolling bearing (1a) to create a large axial or radial overlap which forms an annular gap (25, 26).

Abstract: A tappet (1) is made such that it can be coupled for different valve lifts. To assure a sufficiently rapid supply of hydraulic medium to the coupling means (10) of the tappet (1) in the base circle phase of the cam, according to the invention, the tappet (1) is in permanent hydraulic communication with a supply gallery (23). As a result of this, a pre-pressure of hydraulic medium already prevails in the reservoir (15) in front of the coupling means (10) immediately before the desired coupling, so that the desired coupling of the coupling means (10) can take place sufficiently rapidly even at high speeds of rotation of the internal combustion engine.

Abstract: A worm gear for transforming a rotary motion into a reciprocating (linear) motion comprises a threaded spindle (2) which is mounted for rotation in a gear ring nut (1), a profiled gear ring (5) engaging into a screw thread of the threaded spindle at one peripheral point. The gear ring (5) surrounds the threaded spindle (2), is arranged eccentric to the spindle axis (3) and fixed on an inner ring (8) of a ball bearing (10) surrounding the gear ring (5). The invention provides that, within the gear ring nut (1), the bearings (4) for rotatably mounting the threaded spindle (2) abut against both end faces of the gear ring (5). This results in an easy-to-mount worm gear with a simplified structure.

Abstract: A sealing arrangement for a bearing bushing (1), particularly for a rolling bearing-mounted pin (6) of a cardan joint, said sealing arrangement comprising a rotary shaft seal (8) fixed against rotation on the bearing bush (1) by an armoring (3) and bearing sealingly against the pin (6) with a sealing lip (9), an armored fore-seal (5) disposed in front of the rotary shaft seal (8) and secured against rotation on the pin (6) while being supported on an end face (12) of the bearing bushing (1) wherein the rotary shaft seal (8) is made in one-piece with a rubber packing (15) of a sealing material extending towards the open end of the bearing bush (1) and forming a sealing lip (16) which is supported on an armoring (18) of the fore-seal (5).