An improved elliptical path exercise machine is provided that is simple
and robust in its construction, requires minimal maintenance, provides
smooth even exercise motion, and which has a compact foot-print. The
apparatus includes a pair of planetary gears, sun/ring gears and at least
one crank. The crank is supported and arranged so as to be rotatable
about a crank axis. Each planetary gear is pivotably secured to the crank
about a pivot point located and arranged such that as the crank is
rotated the planetary gears engage and rotate relative to their
corresponding sun/ring gears while simultaneously revolving about the
crank axis so as to form right and left epicylic gear trains. Two foot
pedals are each pivotably secured to a corresponding one of the planetary
gears and are sized and arranged to support the feet of a user. The
layout and geometries of the device are such that each foot-pedal follows
a substantially elliptical foot-path as the crank is rotated. The major
axis of the elliptical foot-path is greater than twice the effective
crank-arm length of the crank so that a compact foot print is attained.