| 主权项 |
1. An elliptical exercise device comprising:
a frame configured to be supported on a horizontal surface, the frame having a first pivot axis defined thereon, the frame further having a forward portion forward of the first pivot axis and a rearward portion rearward of the first pivot axis; a first and a second guide link each having a first and a second attachment point defined thereon, each guide link being pivotally attached, through its first attachment point, to the frame at the first pivot axis thereof, each of the guide links having a guide length defined between the first and second attachment point; a first and a second foot support link each having a foot receiving area configured to support a user's foot thereupon, each foot support link being pivotally connected to the second attachment point of a respective one of the guide links so that when the guide links pivot relative to the frame, they each cause the respective foot receiving area to move in a path of travel having a horizontal component of motion, each foot support link further having a coupling point rearward of the respective pivotal connection to the respective guide link; a cam drive having a first and second cam supported for rotation about an axis of rotation and a first and a second pivoting arm engaging the respective first and second cams such that rotation of the cams causes movement of the pivoting arms; a first and a second vertical control guide disposed on the rearward portion of the frame, spaced from the first pivot axis; a first and a second flexible element each coupling a respective one of the foot support links to a respective one of the pivoting arms of the cam drive, each flexible element having a first end connected to a respective one of the pivoting arms, a second end connected to the coupling point on the respective foot support link, and a midportion extending over a respective one of the vertical control guides on the frame such that rotation of the cams moves the foot receiving areas of the foot support links in a path of travel having a vertical component of motion; each of the flexible couplings having a foot support portion extending between the coupling point on the respective foot support link and the respective vertical guide on the frame, the foot support portion being generally parallel to the respective guide link throughout the motion of the device, the foot support portion further having a length that is similar to the guide length when the respective foot support link is at a midpoint of vertical travel; and the respective first attachment point, second attachment point, guide on the frame and coupling point on the foot support portion generally define a parallelogram when the respective foot support link is at the midpoint of vertical travel; a crank supported for rotation about an axis of rotation; and a first and a second horizontal control link each having a first end connected to the crank and a second end connected to a respective one of the guide links such that as the crank rotates, the horizontal control links pivot the guide links about the first pivot axis, thereby moving the foot receiving areas of the foot support links in a path of travel having a horizontal component of motion, movement of each foot receiving area in the path of travel having a horizontal component of motion being generally out of phase with the movement in the path of travel having a vertical component of motion such that when the horizontal component of motion of each foot receiving area is at its forwardmost or rearwardmost limit, the vertical component of motion of the same foot receiving area is approximately midway between its uppermost and lowermost limit; whereby the foot receiving area of each foot support link moves in a generally elliptical path when the cam portion rotates about the cam axis. |
