Sprocket mechanism for a multistage bicycle

• US 5,545,096 A
• Filed: 08/29/1995
• Issued: 08/13/1996
• Est. Priority Date: 08/29/1995
• Status: Expired due to Fees

• Current Assignee: Bor-Lin Su
• Original Assignee: Bor-Lin Su
• Inventors: Su, Bor-Lin
• Primary Examiner(s): Schoeppel, Roger J.
• Application Number:
  US08/520,598
• Time in Patent Office: 350 Days
• Field of Search: 474/152, 474/153, 474/160, 474/164
• US Class Current: 474/160
• CPC Class Codes: B62M 9/10 involving different-sized wheels, e.g. rear sprocket chain wheels selectively engaged by the chain, belt, or the like bicycle hubs rotatably arranged on axle B60B27/023

Abstract

A sprocket mechanism is provided. The sprocket mechanism includes two or more sprockets each having two groups of teeth formed in the peripheral portion and having another tooth formed between the two groups of teeth. The tooth disposed between the two groups of teeth has a smaller height than the other teeth, and has a straight and tapered surface for facilitating the shifting of the driving chain between the sprockets. The teeth of one of the groups of teeth each includes a pair of diagonal areas, each diagonal area having a tapered cutout portion for preventing the driving chain from shifting between the teeth of that group on each of the sprockets.

Claims

1. A sprocket mechanism for engagement with a driving chain of a bicycle, said sprocket mechanism comprising:

at least two sprockets, each of said sprockets having a peripheral portion on which is formed at least one set of teeth defined by (1) a first group of teeth, said first group of teeth being defined by a plurality of sequentially arranged teeth of a first style, (2) a second group of teeth, said second group of teeth being defined by a plurality of sequentially arranged teeth of a second style, and (3) a tooth of a third style disposed between said first and second groups, each said sprocket having at least one recess formed in a side surface thereof adjacent said peripheral portion, said recess being disposed adjacent said first group of teeth and extending for a distance substantially equal to a width dimension of two consecutive teeth of said first group of teeth, said tooth of said third style having a height dimension less than a height dimension of both said teeth of said first style and said teeth of said second style for facilitating shifting of the driving of a bicycle between said at least two sprockets.

2. The sprocket mechanism as recited in claim 1, where said tooth of said third style includes a straight and tapered surface facing toward said first group of teeth for facilitating shifting of the driving chain between said at least two sprockets.