A belt-tensioning device, in particular for an internal combustion engine, the belt-tensioning device including a bearing housing having a latching recess, a tensioning roller, a pivoting arm and a locking device. The pivoting arm is mounted on the bearing housing, the pivoting arm being under a torsion spring load. The tensioning roller being coupled to the pivoting arm. The locking device having a first latching device and a second latching device. The first latching device and the second latching device being coupled with the pivoting arm. The latching recess interacts with at least one of the first latching device and the second latching device wherein the locking device is configured in such a way that the pivoting arm can be locked by the locking device in different predefined latching positions and the pivoting arm can be pivoted with predefined freedom in an operating position.

To provide a simple-structured chain guide assembly frame capable of reliably maintaining a correct positional relationship between a driven sprocket and a sprocket holding portion without the possibility of driven sprocket detachment. The chain guide assembly frame includes a main body having a fixed-guide-side sprocket holding portion and a pivoting-guide-side sprocket holding portion. The fixed-guide-side sprocket holding portion includes a first fixed-guide-side support portion that supports a driven sprocket at a first contact point, and a second fixed-guide-side support portion that supports the driven sprocket at a second contact point located more outside than the first contact point. When the driven sprocket is in an erected state in which the driven sprocket is supported at the first contact point and second contact point, the vector of gravity acting on the gravity center of the driven sprocket points between the first contact point and second contact point.

A magneto timing control system is described. The magneto timing control system can include an element configured to adjust tension of one of a first section of a belt and a section of the belt, wherein the belt is in communication with at least one magneto. The tension of the first section of the belt and the second section of the belt control a timing advance and a timing retard of the at least one magneto.

The invention provides a simple-structured tensioner lever capable of suppressing deflection of a stopper member and allows smooth assembly of the tensioner lever into an engine. The tensioner lever includes a stopper member for locking a coil spring, this stopper member including: a stopper pin portion inserted into a pin hole; a stopper front side extension portion continuous with one end of the stopper pin portion and protruding toward a base front surface; a stopper rear side extension portion continuous with the other end of the stopper pin portion and protruding toward a base rear surface; a spring lock portion formed in the stopper rear side extension portion and making engagement with a spring support arm; and a stopper movement restricting portion making engagement with the spring support arm to restrict movement of the spring support arm in a direction away from the base rear surface.

A hydraulic auto-tensioner includes a cylinder, a valve sleeve, a rod, a spring seat, and a plunger slidably fitted on the outer diameter surface of the rod. A first leakage gap is defined between the fitting surfaces of the plunger and the rod. A second leakage gap is defined between the fitting surfaces of the plunger and the valve sleeve such that the resistance to oil flowing in the second leakage gap is larger than the resistance to oil flowing in the first leakage gap. With the engine running normally, when the tension of the belt increases, and thus a pushing force is applied to the hydraulic auto-tensioner such that the cylinder and the spring seat are pushed toward each other, oil in a pressure chamber leaks through the first leakage gap into a reservoir chamber.

In order to prevent noise, a ratchet clip and grooves for the ratchet clip to engage are added to the second piston, such that the second piston cannot hit the bottom of the second bore housing. The second piston is prevented from hitting the bottom of the second bore housing by the ratchet clip engaging the ratchet grooves on the outer circumference of the second piston.

A pulley device for a belt that includes an eccentric adjusting member fixed on a support, an eccentric hub rotatably mounted on the eccentric adjusting member, a torsion spring between the eccentric adjusting member and hub to exert a biasing force, and a pulley rotatably mounted on the hub. The hub provides an upper radial surface and the eccentric adjusting member provides a radially outwardly projecting flange formed at an upper end of the eccentric adjusting member and forming an axial abutment for the upper radial surface. The upper radial surface provides a pair of axially projected stops formed integrally within, each stop being dedicated to come into abutment against a corresponding stop provided by the radially outwardly projecting flange of the eccentric adjusting member. The hub further provides engaging means adapted to cooperate with an external tool, the engaging means circumferentially located between the projected stops of the hub.

A crusher belt tensioning apparatus is arranged for being mounting on a crusher having a driven crusher pulley to actuate a crusher, a drive pulley drivable by a power unit, a belt extending between the crusher pulley and the drive pulley to transfer drive from the power unit to the crusher, and a tension drum mounted on a tension arm for applying a tension force to the belt. The tension arm includes a first relatively short arm portion and a second relatively long arm portion connected to the first relatively short arm portion. The tension drum is movable by a hydraulic cylinder, attached to the relatively short arm portion, between a first belt tensioning operating position in which the tension drum applies tension to the belt and a second belt non-tensioning maintenance position in which the belt is removable from the tensioning apparatus.

A tensioner is disclosed. The tensioner includes an arm, a tong, and a clutch. The arm is rotatable about a first axis in an opposite direction. The arm includes at least one stopping element. The tong is selectively engaged with the at least one stopping element of the arm. The arm is substantially prevented from rotating in the opposite direction if the tong is engaged with the at least one stopping element. The clutch is operatively coupled to the arm. The clutch includes an engaged and a disengaged position. If the clutch is in the engaged position, then the tong is engaged with the at least one stopping element of the arm.

An assembly comprising: a fixed support such as an engine block, a plurality of pulleys mounted rotatably on the support a belt mounted on said pulleys a tensioner comprising: a plate a rotary element mounted on the plate via a rotating shaft fixed relative to said plate, the tensioner being capable of turning relative to the support, in a predefined direction of rotation, between an idle position in which the rotary element is separated from the belt and an operating position in which the rotary element is in contact with the belt, it being specified that, in the operating position, the belt exerts a force on the rotary element, the direction of said force tending to rotate the tensioner in said same predefined direction of rotation; at least one stop for preventing the tensioner from rotating in the predefined direction of rotation beyond the operating position of same, the latter thus being defined by the stop; wherein in order to rotate the tensioner relative to the support between the idle position and the operating position of the tensioner, the assembly comprises: at least one closed port arranged on the plate of the tensioner or on the support at least one means for engaging with the or each closed port, said engaging means being fixed relative to the support when the closed port is located on the plate or fixed relative to the plate when the closed port is located on the support.