A device for tensioning a roller chain in a chain drive system is disclosed. The device includes a floating shoe with a surface upon which the chain may slide and a housing. A tension force provided by a tension mechanism is directed from the housing to the floating shoe in an outward direction with respect to the path of the roller chain. A retention feature limits the distance the floating shoe may travel with respect to the housing.

Tensioning apparatus (10, 30, 130) for applying a required tension to a line means (12, 32, 132). A body (14, 34, 134) is provided which provides first (26, 50, 150), second (20, 60, 160) and third (28, 52, 152) parts with contact surfaces engagable with the line means so as to urge the line means from a straight alignment to provide a required tension therein. The second part (60, 62) may be adjustably movable relative to the first (50, 150) and third (52, 152) parts.

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.

In one embodiment, the present invention relates to a belt tensioning device for a hollow blind that comprises: a holder seat equipped with a lower belt gear on the top portion of the holder, the holder seat is in clearance fit with a lumen of a side frame of the hollow blind and is provided with a group of V-shaped slots from top to bottom therein, each V-shaped slot is equipped with a clip therein, the slip has a width slightly larger than the width of the lumen of the side frame of the hollow blind when being bent. The present invention allows the belt tensioning device to move along a single direction within the side frame of the hollow blind so that the distance between two belt gears can be gradually adjusted, thereby maintaining a proper tensioning force in the belt.

A tensioner comprising a carrier pivotably mountable to a mounting surface, an arm having a first pulley journalled thereto and a second pulley journalled thereto, the arm slidingly engaged with the carrier for a linear movement with respect to a carrier axis A-A, and a spring disposed between the carrier and the arm, the spring resisting an arm movement along carrier axis A-A.

A hydraulic tensioning device for a chain drive, having a tensioning piston which is guided in a holder and which, on its outer circumferential surface, has locking grooves, an inner guide which projects into a cavity of the piston, and a locking element which has at least two annular sections and at least two radial extensions, wherein the locking element can be placed in engagement by the at least two annular sections with one of the locking grooves, and having a clamping stop and a sliding stop which are axially spaced apart from one another. To simplify the structural design, the holder has at least two axial extensions which extend in an axial direction between the clamping stop plane and the sliding stop plane, wherein the at least two axial extensions and the tensioning piston do not enclose the at least two radial extensions.

A belt tensioner (1) for a generator belt drive of an internal combustion engine is provided. The belt tensioner includes a tensioning arm (5) with a tensioning roller (7) mounted thereon, and a tensioning spring which acts on the tensioning arm and is intended for pretensioning the belt (11) is designed for mounting onto the generator (2) and, in the mounted state of the belt drive, engages annularly around the belt pulley (6) of the generator and encompasses the belt in a plane which is spaced apart from the plane of the belt and runs on the far side of the belt plane with respect to the generator. The belt tensioner has an open ring-shaped construction, and therefore, in the mounted state of the belt tensioner on the generator, the belt can be mounted axially through the ring opening (9, 10) in the belt tensioner onto the belt pulley of the generator.

Provided is a tensioner which has a small total number of components and no risk of incorrect assembly, allows easy load change, is easy to assemble, and excellently stabilizes an oil pressure in a pressure oil chamber. The tensioner 100 includes a relief mechanism that relieves oil to the outside of a plunger 110 when the oil pressure in the pressure oil chamber formed between the plunger 110 and a plunger containing hole 121 in a housing 120 increases, relief holes 141 extending through the plunger 120 from the inside of a plunger inner space 111 to an outer circumferential side thereof, and a hole closing member 142 that is pressed into an opening of each of the relief holes 141 on the outer circumferential side.

A reversible drive belt system comprises a drive belt, a forward direction drive motor, and a reverse direction hydraulic drive motor. A belt tensioning element has a force applied to it by a first tensioning system and a second tensioning system in the form of a hydraulic cylinder. When the drive system is operated in the reverse direction, an input hydraulic pressure to the hydraulic cylinder is controlled in dependence on a load on the hydraulic motor.

Ring tensioners having a plurality of rungs that extend from a first side to an opposite second side of the ring tensioner, in use, the rungs engaging between the teeth of a toothed belt. Both the first side and the second side of the ring tensioner are not continuous but have gaps. The gaps on the first side alternate with the gaps on the second side. The ring tensioners may be formed from a single length of wire.