A cycling aid
OwnerAlan John ROBINSONinventor
Life of this patent
Estimating the term…
Abstract
A crank arm for a bicycle chainset is provided. The arm comprises means for varying crank length during rotation, whereby to gain mechanical advantage.
Claims15
A crank arm for a bicycle chainset, the arm having a varying crank length during rotation whereby to gain mechanical advantage, wherein the arm comprises two or more sections movable relative to each other and means for attracting and/or repelling the section to/from each other to cause the variation in length.
(canceled)
(canceled)
8-14. (canceled)
(canceled)
A bicycle foot pedal mechanism comprising two cranks, each crank carrying a pedal, each of the cranks comprising two or more sections movable relative to each other, and the cranks being automatically extendible and retractable dependent upon rotation extent to cause variation in length during rotation whereby to gain a mechanical advantage.
A method of gaining mechanical advantage for a bicycle foot pedal mechanism comprising:
- i) providing a chainset having two crank arms, each crank arm carrying a pedal and each arm being extendible and retractable so as to have a variable crank length;
- ii) monitoring the rotational extent of the pedals;
- iii) initiating extension of each arm when its respective pedal is near top dead centre;
- and iv) initiating retraction of each arm before said each arm reaches bottom dead centre so that said each arm does not hit the ground.
Dependencies are inferred from the claim text.