Sprocket structure and chain guard

A compound sprocket structure particularly advantageous for use in a bicycle or other vehicle comprising at least two plate segments each of which has a peripheral edge formed to include a set of teeth, one of said plate segments being offset from the other to provide that said plate segments are arranged thereby to lie in adjacent substantially parallel planes, one of said plate segments being rimmed by and lying within the boundary of the other and the outer of said plate segments having an annular shape, and connector means joining said plate segments and forming a continuation of the plate form thereof, said structure having the appearance of a plate having a dished configuration, the central portion and base of said dish being provided by said one plate segment, which has a disc-like shape.

A spocket structure particularly advantageous for use in a bicycle or other vehicle comprising a plate formed to include therein a plurality of concentric plate portions which are relatively displaced to occupy offset substantially parallel planes, said plate having a dished configuration, the base of said dish being formed by a central portion thereof which has a disc-like shape, said central dished portion being relatively flat and the peripheral edge thereof being formed to include thereon a set of circularly spaced outwardly projected sprocket teeth, the outer peripheral edge of said disc-like portion of said plate embodying therein a series of circularly spaced notches, at the base of at least a portion of which notches said disc-like portion of said plate has joined thereto and extended radially outward therefrom strip-like portions of said plate which are offset and connected at their radial outermost ends in an integrated relation to an outer one of said concentric plate portions to maintain said outer one of said concentric plate portions in a rigidly connected and respectively fixed relation to said disc-like portion of said plate and said disc-like portion of said plate including, in integral connection therewith, means for mounting a guard to said sprocket structure without need for conventional fasteners.

A sprocket and chain guard assembly including a single element having the form of a plate formed to include therein a plurality of concentric plate portions which are relatively displaced to occupy offset substantially parallel planes, one of said concentric plate portions forming a central part of said plate element and being dished inwardly of the outer peripheral portion of said plate element which forms another of said concentric plate portions, said relatively dished central portion being peripherally toothed and forming a substantially flat sprocket surrounded and recessed relative to an outwardly positioned annular portion of said plate element which is peripherally toothed and defines a sprocket of larger diameter, and a dish shaped plate forming a chain guard mounting in a nesting relation to said plate element and seating to said central flat sprocket portion thereof and means embodied in said central flat sprocket and said chain guard for a releasable interconnection thereof by a rotation of one relative the other.

A chain guard for use in conjuction with a sprocket structure comprising a plate a central portion of which is relatively recessed with respect to its outer peripheral portion, said central portion embodying means therein to interfit with related sprocket structure by a rotary movement of one relative the other.

A sprocket structure comprising a single plate formed as a stamping from sheet material wherein a central portion thereof is dished relative to an outer peripheral portion and each said portion is formed to include a set of circularly spaced outwardly projected sprocket teeth and portions of said plate intermediate said central portion and said outer peripheral portion being formed as a web to maintain said central portion and said outer peripheral portion in substantially parallel planes.