Multi-speed sprocket assembly
View Patent ↗A multi-speed sprocket assembly configured to receive a bicycle chain including a plurality of pairs of inner link plates, a plurality of pairs of outer link plates and plurality of rollers connecting the pairs of inner and outer link plates. The multi-speed sprocket assembly generally includes a smaller diameter sprocket and a larger diameter sprocket rotated about a rotation axis in a driving direction. The smaller and larger diameter sprockets include first and second pluralities of teeth spaced about their peripheries, respectively. The larger diameter sprocket has an inboard side including first and second projections axially extending therefrom. The second projection is disposed circumferentially aft, opposite the driving direction, and radially outwardly of the first projection. The first and second projections simultaneously support one outer link plate as the bicycle chain shifts from the smaller diameter sprocket to the larger diameter sprocket.
1. A multi-speed sprocket assembly for receiving a bicycle chain including a plurality of pairs of inner link plates, a plurality of pairs of outer link plates and plurality of rollers connecting the pairs of inner and outer link plates, the multi-speed sprocket assembly comprising:
a smaller diameter sprocket having a first plurality of teeth spaced about a periphery thereof, the smaller diameter sprocket rotated about a rotation axis in a driving direction; and
a larger diameter sprocket having a second plurality of teeth spaced about a periphery thereof, the larger diameter sprocket rotated about the rotation axis in the drive direction, the larger diameter sprocket having an inboard side including first and second projections axially extending therefrom, the second projection disposed circumferentially aft, opposite the driving direction, and radially outwardly of the first projection, the first and second projections simultaneously supporting the same outer link plate as the bicycle chain shifts from the smaller diameter sprocket to the larger diameter sprocket.
2. The multi-speed sprocket assembly of claim 1 wherein the first projection has a first support surface sloped to form an acute angle with the rotation axis.
3. The multi-speed sprocket assembly of claim 2 wherein the second projection has a second support surface substantially parallel to the rotation axis.
4. The multi-speed sprocket assembly of claim 3 wherein the first and second projections are rivets.
5. The multi-speed sprocket assembly of claim 3 wherein the second plurality of teeth include first and second chain-receiving teeth, the first chain-receiving tooth disposed adjacent to and circumferentially aft of the second projection, the second chain-receiving tooth disposed circumferentially aft of the first chain-receiving tooth.
6. The multi-speed sprocket assembly of claim 5 wherein the first and second chain-receiving teeth have shaved tips disposed radially inwardly of the adjacent teeth.
7. A multi-speed sprocket assembly for engaging a bicycle chain comprising:
a smaller diameter sprocket having a first plurality of teeth spaced about a periphery thereof, the smaller diameter sprocket rotated about a rotation axis; and
a larger diameter sprocket having a second plurality of teeth spaced about a periphery thereof, the larger diameter sprocket rotated about the rotation axis, the larger diameter sprocket having an inboard side including a ridge defining a ridge plane perpendicular to the rotation axis, the ridge guiding the bicycle chain as the bicycle chain shifts from the larger diameter sprocket to the smaller diameter sprocket, the inboard side of the larger diameter sprocket including a recess disposed radially inwardly of the ridge and outboard of the ridge plane, the recess disposed adjacent a portion of the bicycle chain engaged with the smaller diameter sprocket, the recess permitting silent running of the chain.
8. The multi-speed sprocket assembly of claim 7 wherein the recess is formed circumferentially about the rotation axis.
9. The multi-speed sprocket assembly of claim 8 wherein the ridge is configured such that a radially outermost perimeter of a portion of the bicycle chain engaged with the smaller diameter sprocket is disposed radially inwardly of the ridge.
10. A multi-speed sprocket assembly for engaging a bicycle chain comprising:
a smaller diameter sprocket having a first plurality of teeth spaced about a periphery thereof, the smaller diameter sprocket rotated about a rotation axis; and
a larger diameter sprocket having a second plurality of teeth spaced about a periphery thereof, the larger diameter sprocket rotated about the rotation axis, the larger diameter sprocket having an inboard side including a ridge defining a ridge plane perpendicular to the rotation axis, the ridge guiding the bicycle chain as the bicycle chain shifts from the larger diameter sprocket to the smaller diameter sprocket, the inboard side including a concave contour extending radially from a tooth root to the ridge.
11. The multi-speed sprocket assembly of claim 10 wherein the concave contour extends from the ridge and smoothly asymptotes into a vertical plane perpendicular to the rotation axis toward the tooth root.
12. The multi-speed sprocket assembly of claim 11 wherein the concave contour extends circumferentially about the rotation axis.
13. A multi-speed sprocket assembly for receiving a bicycle chain including a plurality of pairs of inner link plates, a plurality of pairs of outer link plates and plurality of rollers connecting the pairs of inner and outer link plates, the multi-speed sprocket assembly comprising:
a smaller diameter sprocket having a first plurality of teeth spaced about a periphery thereof, the first plurality of teeth including a reference tooth, the smaller diameter sprocket rotated about a rotation axis in a drive direction; and
a larger diameter sprocket having a second plurality of teeth spaced about a periphery thereof, the second plurality of teeth including first and second chain-receiving teeth, the larger diameter sprocket rotated about the rotation axis in the drive direction, the larger diameter sprocket having an inboard side including first and second projections axially extending therefrom, the second projection disposed circumferentially aft, opposite the drive direction, and radially outwardly of the first projection,
the first projection supporting a leading end of an outer link plate of a first pair of outer link plates when the reference tooth of the smaller sprocket engages between a pair of inner link plates and the first chain-receiving tooth engages between a second pair of outer link plates positioned aft of the first pair of outer link plates as the bicycle chain shifts from the smaller sprocket to the larger sprocket,
the first projection supporting a trailing end of the outer link plate of the first pair of outer link plates, when the reference tooth of the smaller sprocket engages between a pair of outer link plates and the second chain-receiving tooth engages between the second pair of outer link plates as the bicycle chain shifts from the smaller sprocket to the larger sprocket.
14. The multi-speed sprocket assembly of claim 13 wherein the second projection supports the leading end of the outer link plate of the first pair of outer link plates when the first projection supports the trailing end of the outer link plate of the first pair of outer link plates.
15. The multi-speed sprocket assembly of claim 14 wherein the first projection has a first support surface sloped to form an acute angle with the rotation axis.
16. The multi-speed sprocket assembly of claim 15 wherein the second projection has a second support surface substantially parallel to the rotation axis.
17. The multi-speed sprocket assembly of claim 16 wherein the first and second projections are rivets.
18. The multi-speed sprocket assembly of claim 17 wherein the second plurality of teeth include first and second chain-receiving teeth, the first chain-receiving tooth disposed adjacent to and circumferentially aft of the second projection, the second chain-receiving tooth disposed circumferentially aft of the first chain-receiving tooth.