A belt tensioning device comprises a base member having an attachment portion and an opening for a drive shaft; first and second tensioning arms that are pivotably supported by first and second bearings on the base member around first and second pivot axes and have first and second tensioning rollers 5, 7. A spring arrangement pretensions the two tensioning arms in a circumferential direction towards each other; wherein the spring arrangement has at least one bow-shaped spring that has a circumferential extension of less than 360° around the first and the second pivot axis; wherein the at least one bow-shaped spring has first and second support portions that are supported on the first and second tensioning arm as well as a spring portion extending between the first and second support portion; wherein the at least one bow-shaped spring has an axial length in the area of the first and the second support portion which is axially shorter than a total axial length of the bow-shaped spring.

A belt tensioning device comprises a base member having an attachment portion and an opening for a drive shaft; first and second tensioning arms that are pivotably supported by first and second bearings on the base member around first and second pivot axes and have first and second tensioning rollers 5, 7. A spring arrangement pretensions the two tensioning arms in a circumferential direction towards each other; wherein the spring arrangement has at least one bow-shaped spring that has a circumferential extension of less than 360° around the first and the second pivot axis; wherein the at least one bow-shaped spring has first and second support portions that are supported on the first and second tensioning arm as well as a spring portion extending between the first and second support portion; wherein the at least one bow-shaped spring has an axial length in the area of the first and the second support portion which is axially shorter than a total axial length of the bow-shaped spring.

The problem to be solved is to provide a tensioner lever that inhibits friction-induced wear or seizure on a surface of a pivoting support boss contacting a shoulder bolt so that high durability is achieved, and that is easily producible and enables cost reduction. As a solution to the problem noted above, the tensioner lever includes a shoe having a traveling surface, a lever body, and a pivotal support boss provided at a proximal end of the lever body to allow a distal end thereof to swing. The shoe and the lever body are integrally formed and assembled together by double injection molding. The lever body includes a slide bearing member, and a connecting part that connects the slide bearing member and the shoe. The slide bearing member, the connecting part, and the shoe are made of the same synthetic resin, and configured as a continuous one-piece component.

The problem to be solved is to provide a tensioner lever that inhibits friction-induced wear or seizure on a surface of a pivoting support boss contacting a shoulder bolt so that high durability is achieved, and that is easily producible and enables cost reduction. As a solution to the problem noted above, the tensioner lever includes a shoe having a traveling surface, a lever body, and a pivotal support boss provided at a proximal end of the lever body to allow a distal end thereof to swing. The shoe and the lever body are integrally formed and assembled together by double injection molding. The lever body includes a slide bearing member, and a connecting part that connects the slide bearing member and the shoe. The slide bearing member, the connecting part, and the shoe are made of the same synthetic resin, and configured as a continuous one-piece component.

A tensioning rail (2) for tensioning an endlessly circulating tensioner (4) is provided, wherein the tensioning rail (2) for tensioning the ternsioner (4) is curved in a longitudinal direction (L), the tensioning rail (2) has a base wall (6) and two jaws (8) protruding from the base wall (6), and the tensioning rail (2) has at least one U-shaped profiled segment (10) and a T-shaped profiled segment (12), which are each formed by the base wall (6) and the jaws (8), wherein the tensioning rail (2) includes a guiding element (14) for a rotary bearing (16) in the U-shaped profiled segment (10) and a guiding element (18) for a contact bearing (20) in the T-shaped profiled segment (12).

A tensioning rail (2) for tensioning an endlessly circulating tensioner (4) is provided, wherein the tensioning rail (2) for tensioning the ternsioner (4) is curved in a longitudinal direction (L), the tensioning rail (2) has a base wall (6) and two jaws (8) protruding from the base wall (6), and the tensioning rail (2) has at least one U-shaped profiled segment (10) and a T-shaped profiled segment (12), which are each formed by the base wall (6) and the jaws (8), wherein the tensioning rail (2) includes a guiding element (14) for a rotary bearing (16) in the U-shaped profiled segment (10) and a guiding element (18) for a contact bearing (20) in the T-shaped profiled segment (12).

A tensioning device (1) for tensioning a traction mechanism of a traction mechanism drive, including a housing (2), a piston (3) that is mounted such that the piston can be displaced in an axial direction inside the housing (2), and a transport securing element (4), which in at least one transport position of the tensioning device (1) is arranged in the housing (2) transversely to the piston (3) and in abutment with the piston (3) such that a displacement of the piston (3) in at least one first axial direction is blocked. The transport securing element (4) is provided with a support portion (5), wherein in the transport position at least one first web area (6) of the support portion (5) is in abutment with one end face (7) of the piston (3), and an additional web area (8) of the support portion (5) extending in an axial direction away from the first web area (6) is supported in the housing (2), at least in a radial direction.

A tensioning device (1) for tensioning a traction mechanism of a traction mechanism drive, including a housing (2), a piston (3) that is mounted such that the piston can be displaced in an axial direction inside the housing (2), and a transport securing element (4), which in at least one transport position of the tensioning device (1) is arranged in the housing (2) transversely to the piston (3) and in abutment with the piston (3) such that a displacement of the piston (3) in at least one first axial direction is blocked. The transport securing element (4) is provided with a support portion (5), wherein in the transport position at least one first web area (6) of the support portion (5) is in abutment with one end face (7) of the piston (3), and an additional web area (8) of the support portion (5) extending in an axial direction away from the first web area (6) is supported in the housing (2), at least in a radial direction.

In an aspect, a power transfer device, such as a decoupler, is provided for transferring torque between a shaft and a belt. The device includes: a hub configured to 5 couple to the shaft, a pulley rotatably coupled to the hub that includes a power transmitting surface configured to engage the belt, an isolation spring to transfer a rotational load from one of the pulley and the hub to the other of the pulley and the hub, optionally a one-way clutch to permit overrunning of one of the pulley and the hub relative to the other of the pulley and the hub in a first direction, and a damping member 10 positioned to be driven into frictional engagement with a friction surface by a force from the isolation spring acting on the damping member that varies based on the rotational load transferred by the isolation spring.

A manual drive assembly for a manually-operated window treatment based on a drive chain formed as a loop, may incorporate one or more intermediate tensioners disposed between two ends of the loop. The loop may be formed between a manual clutch mechanism coupled to the window treatment and an end tensioner. The one or more intermediate tensioners may serveto limit slack in the loop such that sides of the loop cannot be pulled to create a large loop, for example, having a gap of four inches or greater, between the hanging sides of the cord.