Abstract: The invention provides a chain and a chain guide plate that suppress occurrence of noise during chain traveling while attaining a reduction in costs and also attaining space saving. A chain includes first plate rows and second late rows. Each of the first plate rows includes a guide plate including a guide slide contact section for coming into slide contact with an inner side guide. The guide slide contact section extends in a chain longitudinal direction to be asymmetrical relative to an imaginary center line. During guiding by the inner side guide, lines drawn by the guide slide contact sections of a plurality of the guide plates are continuous in the chain longitudinal direction.

Abstract: The invention provides a chain and a chain guide plate that suppress occurrence of noise during chain traveling while attaining a reduction in costs and also attaining space saving. A chain includes first plate rows and second late rows. Each of the first plate rows includes a guide plate including a guide slide contact section for coming into slide contact with an inner side guide. The guide slide contact section extends in a chain longitudinal direction to be asymmetrical relative to an imaginary center line. During guiding by the inner side guide, lines drawn by the guide slide contact sections of a plurality of the guide plates are continuous in the chain longitudinal direction.

Abstract: In a ratchet type chain tensioner, having a toothed rack on its plunger and a pawl cooperable with the rack, a recess is provided between the front end of the rack and the protruding end of the plunger. In the initial stages of operation of the tensioner, the pawl can enter the recess while permitting the plunger to protrude and retract freely within a limited range. Thereafter, when the chain controlled by the tensioner becomes elongated, the pawl cooperates with the rack to limit retraction of the plunger.

Abstract: In a chain transmission a standard ISO roller chain meshes with a modified sprocket having a root diameter larger than the root diameter of a standard sprocket designed for use with the standard chain. The angular tooth pitches can be either of two kinds. In a first version, the sprocket has two irregularly distributed tooth pitches, ???? and ?+2??, there being two tooth pitches ???? for each tooth pitch ?+2??. In a second version, the sprocket has three angular tooth pitches, ????, ?, and ?+??, in equal numbers, also distributed irregularly.

Abstract: In a ratchet type chain tensioner, having a toothed rack on its plunger and a pawl cooperable with the rack, a recess is provided between the front end of the rack and the protruding end of the plunger. In the initial stages of operation of the tensioner, the pawl can enter the recess while permitting the plunger to protrude and retract freely within a limited range. Therafter, when the chain controlled by the tensioner becomes elongated, the pawl cooperates with the rack to limit retraction of the plunger.

Abstract: In a chain transmission incorporating a standard roller chain, the diameter of the tooth gap bottom circle of a sprocket in mesh with the chain, is greater than the diameter of the tooth gap bottom circle for a corresponding sprocket having an ISO tooth form.