A power transmission chain (2) for use with a drive member (4) having a plurality of teeth (6), and wherein: (i) the power transmission chain (2) comprises a plurality of chain links (8) which are pivotally connected together by connecting members (9) and pivot arrangements (10) so that the power transmission chain (2) can pass around the drive member (4) in use; (ii) each one of the pivot arrangements (10) comprises first and second pivots (12, 14) which extend towards each other from opposite sides (16, 18) of the chain links (8); (iii) the first and second pivots (12, 14) have adjacent ends (20, 22) which face each other and which are spaced apart; (iv) the power transmission chain (2) comprises a plurality of engaging formations (24) for enabling engagement with the drive member (4); (v) the engaging formations (24) are positioned between the adjacent ends (20, 22) of the first and second pivots (12, 14); and the engaging formations (24) and the spacing apart of the adjacent ends (20, 22) of the first and second pivots (12, 14) cause the power transmission chain (2) in use always to be positioned on the drive member (4) for maximum efficiency of drive transfer between the drive member (4) and the power transmission chain (2), and irrespective of the diameter of the drive member (4).

A power transmission chain (2) for use with a drive member (4) having a plurality of teeth (6), and wherein: (i) the power transmission chain (2) comprises a plurality of chain links (8) which are pivotally connected together by connecting members (9) and pivot arrangements (10) so that the power transmission chain (2) can pass around the drive member (4) in use; (ii) each one of the pivot arrangements (10) comprises first and second pivots (12, 14) which extend towards each other from opposite sides (16, 18) of the chain links (8); (iii) the first and second pivots (12, 14) have adjacent ends (20, 22) which face each other and which are spaced apart; (iv) the power transmission chain (2) comprises a plurality of engaging formations (24) for enabling engagement with the drive member (4); (v) the engaging formations (24) are positioned between the adjacent ends (20, 22) of the first and second pivots (12, 14); and the engaging formations (24) and the spacing apart of the adjacent ends (20, 22) of the first and second pivots (12, 14) cause the power transmission chain (2) in use always to be positioned on the drive member (4) for maximum efficiency of drive transfer between the drive member (4) and the power transmission chain (2), and irrespective of the diameter of the drive member (4).

The present invention is a chain structure of bicycles, which comprises a plurality of rollers, a plurality of chain sheets and a plurality of chain rollers. Wherein the rollers define a mounting space. Each chain sheet comprises a chain body, a first pivot joint part extending from one end of chain body and to be arranged in the mounting space, a second pivot joint part horizontally extending from the other end of chain body, the second pivot joint part is installed on the roller with the first pivot joint part, wherein the first pivot joint part is in a horizontal position different from chain body, the first pivot joint part defines a rotation space for placing the second pivot joint part of another chain sheet, so that the first pivot joint part and second pivot joint part can rotate a preset angle in the rotation space. When the chain sheets are combined with rollers respectively, the chain bodies remain on the same plane, the chain roller penetrates the second pivot joint part and the first pivot joint part respectively for connecting the roller to the chain sheets on both sides of roller. Thereby, the chain is thinned and the weight is reduced, the tensile strength is increased by thickening the chain sheet.

The present invention is a chain structure of bicycles, which comprises a plurality of rollers, a plurality of chain sheets and a plurality of chain rollers. Wherein the rollers define a mounting space. Each chain sheet comprises a chain body, a first pivot joint part extending from one end of chain body and to be arranged in the mounting space, a second pivot joint part horizontally extending from the other end of chain body, the second pivot joint part is installed on the roller with the first pivot joint part, wherein the first pivot joint part is in a horizontal position different from chain body, the first pivot joint part defines a rotation space for placing the second pivot joint part of another chain sheet, so that the first pivot joint part and second pivot joint part can rotate a preset angle in the rotation space. When the chain sheets are combined with rollers respectively, the chain bodies remain on the same plane, the chain roller penetrates the second pivot joint part and the first pivot joint part respectively for connecting the roller to the chain sheets on both sides of roller. Thereby, the chain is thinned and the weight is reduced, the tensile strength is increased by thickening the chain sheet.

A drive sprocket comprising a plurality of teeth for meshing with a drive member to transmit rotary motion, the drive member including a plurality of engagement pockets engaging the teeth of the drive sprocket, wherein each tooth has a tooth profile defined by a first side comprising a first engagement surface and an opposite second side comprising a second engagement surface, which engagement surfaces are configured such that when driven, a tooth meshes to the engagement pocket at a first contact location on the first engagement surface and also at a second contact location on the second engagement surface, wherein the first contact location is radially offset from the second contact location.

A drive sprocket comprising a plurality of teeth for meshing with a drive member to transmit rotary motion, the drive member including a plurality of engagement pockets engaging the teeth of the drive sprocket, wherein each tooth has a tooth profile defined by a first side comprising a first engagement surface and an opposite second side comprising a second engagement surface, which engagement surfaces are configured such that when driven, a tooth meshes to the engagement pocket at a first contact location on the first engagement surface and also at a second contact location on the second engagement surface, wherein the first contact location is radially offset from the second contact location.

A transmission mechanism includes a chain. The chain includes a plurality of inner link units and a plurality of outer link units. Each of the inner link units includes two inner chain plates. Each of the inner chain plates has an inner waist section. At least one of the outer link units includes two outer chain plates. Each of the outer chain plates has an outer waist section that has a protruding part and a recessed part. A distance between the inner waist sections of each of the inner link units is smaller than a distance between the protruding parts of the outer chain plates of the at least one of the outer link units, and is equal to or smaller than a distance between the recessed parts of the at least one of the outer link units.

A transmission mechanism includes a chain. The chain includes a plurality of inner link units and a plurality of outer link units. Each of the inner link units includes two inner chain plates. Each of the inner chain plates has an inner waist section. At least one of the outer link units includes two outer chain plates. Each of the outer chain plates has an outer waist section that has a protruding part and a recessed part. A distance between the inner waist sections of each of the inner link units is smaller than a distance between the protruding parts of the outer chain plates of the at least one of the outer link units, and is equal to or smaller than a distance between the recessed parts of the at least one of the outer link units.

A link connecting structure includes two outer link plates and two inner link plates. An inner side of each outer link plate is formed with a concave portion between two first coupling portions at two ends thereof. A connecting surface is connected between each first coupling portion and the concave portion. The connecting surface is gradually tapered inward from each first coupling portion toward the concave portion. An outer side of each inner link plate is provided with a pair of bent portions each extending from an outermost edge of each second coupling portion toward the connecting surface. A gap is defined between each bent portion and the connecting surface. The gap is less than the minimum thickness of a narrow tooth of a chainring, thereby preventing the tooth from being jammed in the gap.

A link connecting structure includes two outer link plates and two inner link plates. An inner side of each outer link plate is formed with a concave portion between two first coupling portions at two ends thereof. A connecting surface is connected between each first coupling portion and the concave portion. The connecting surface is gradually tapered inward from each first coupling portion toward the concave portion. An outer side of each inner link plate is provided with a pair of bent portions each extending from an outermost edge of each second coupling portion toward the connecting surface. A gap is defined between each bent portion and the connecting surface. The gap is less than the minimum thickness of a narrow tooth of a chainring, thereby preventing the tooth from being jammed in the gap.