Derailleur pulley for use with bicycle derailleur systems

A chain guide pulley for use with a bicycle rear derailleur system, said chain guide pulley comprising:

• a guide sprocket;
• a substantially circular outer periphery of said guide sprocket;
• a plurality of teeth positioned on said outer periphery, said teeth having predetermined width, depth and thickness dimensions, said teeth adapted to engage a drive chain, said teeth thickness dimension being not more than about three-fourths of a minimum distance between opposed pairs of roller link plates of said drive chain;
• a cylindrical shaped inner peripheral surface axially therethrough said guide sprocket, defining thereby a bearing means aperture, said bearing means aperture having a periphery dimensioned to accept therein, into low frictional rotational bearing relationship, a spindle means of said rear derailleur system;
• and
• a plurality of circumferentially spaced-apart debris-clearing apertures, said plurality of apertures located on a concentric between said bearing means and said substantially circularly configured outer periphery.

A chain guide pulley for use with a bicycle rear derailleur system, said chain guide pulley comprising:

• a guide sprocket;
• a substantially circular outer periphery of said guide sprocket;
• a plurality of teeth positioned on said outer periphery, said teeth having predetermined width, depth and thickness dimensions;
• a cylindrical shaped inner peripheral surface axially therethrough said guide sprocket, defining thereby a bearing means aperture, said bearing means aperture having a periphery dimensioned to accept therein, into interfitting relationship, a bearing means, said bearing means having an outer race tightly affixed within said bearing means aperture and having an inner race sized to be attachable to said bicycle rear derailleur system;
• and
• a plurality of circumferentially spaced-apart debris-clearing apertures, said plurality of apertures located on a concentric between said bearing means and said substantially circularly configured outer periphery.

A chain guide pulley for use with a bicycle rear derailleur system, said chain guide pulley comprising:

• a guide sprocket;
• a substantially circular outer periphery of said guide sprocket;
• a plurality of teeth positioned on said outer periphery, said teeth having predetermined width, depth and thickness dimensions, said teeth adapted to engage a drive chain, said teeth thickness dimension being not more than about three-fourths of a minimum distance between opposed pairs of roller link plates of said drive chain;
• a cylindrical shaped inner peripheral surface axially therethrough said guide sprocket, defining thereby a bearing means aperture, said bearing means aperture having a periphery dimensioned to accept therein, into interfitting relationship, a bearing means, said bearing means having an outer race tightly affixed within said bearing means aperture and having an inner race sized to be attachable to said bicycle rear derailleur system;
• and
• a plurality of circumferentially spaced-apart debris-clearing apertures, said plurality of apertures located on a concentric between said bearing means and said substantially circularly configured outer periphery.

In a bicycle having a drive chain, said drive chain having a minimum distance between each of a plurality of opposed pairs of roller link plates, at least two spaced-apart, coaxially mounted rear sprockets, said sprockets having teeth with arcuate roller seats adapted to accept a number of roller bushings of said drive chain, said bicycle also having an improved laterally-adjustable guide means with two rotatable guide pulleys as parts thereof, said guide means adaptable for aligning each of said two rotatable guide pulleys with any one of said sprockets for guiding, with said two rotatable guide pulleys, said drive chain onto any one of said sprockets, said guide means also adapted for causing said drive chain to shift from any one of said sprockets to any other, said improvement of said guide means comprising:

• two improved rotatable guide pulleys each having a substantially circularly configured outer periphery with a plurality of guide pulley teeth thereon adapted to engage said drive chain, said guide pulley teeth thickness dimension being not more than about three-fourths of said minimum distance between said opposed pairs of roller link plates;
• guide pulley bearing means fixedly centered within each said two guide pulleys, said bearing means adapted to permit substantially no lateral movement of said guide pulley teeth relative to said bearing means when said improved guide pulleys are in use for shifting said drive chain from said any one to any other of said sprockets;
• and
• a plurality of circumferentially spaced-apart debris-clearing apertures, said plurality of apertures located on a concentric between said bearing means and said substantially circularly configured outer periphery on each of said improved rotatable guide pulleys.