Multi-speed transmission front gear mechanism for a bicycle

Claim 1

A multi-speed transmission front gear mechanism secured to a crank shaft rotatable by the operation of a pedal, a driving chain for transmitting the rotary power of said crank shaft to a bicycle wheel, said driving chain including spaced apart links and spaced pins interconnecting said links, each adjacent pair of said pins spaced an equal distance apart, said front gear mechanism comprising a low speed gear having dents positioned at equally spaced apart first intervals for engagement with said driving chain and secured to said crank shaft, a high speed gear having a larger diameter than said low speed gear and secured to said crank shaft at the side of said low speed gear, said high speed gear having dents disposed at equally spaced apart second intervals formed in an alternately spaced arrangement relative to the dents of said low speed gear and the spaced apart second intervals being twice the length of said first intervals, whereby when said driving chain is engaged with said high speed gear, the dents of said high speed gear are engaged between every other said pair of pins while when said driving chain is engaged with said low speed the dents of said low speed gear are engaged between every pair of said pins, and a means for securing said low speed and high speed gears to the crank shaft at a regularly laterally spaced apart interval.