Patent ID: 7758478

Claim:
A vertical weight stack for an exercise device comprising: a plurality of weight plates each including an aperture defined by an engagement surface; an engagement assembly supported on the plurality of weight plates, the engagement assembly including a longitudinal member with a plurality of longitudinally spaced projections, the longitudinal member defining a longitudinal axis; and a lock member operably associated with the longitudinal member to selectively lock the rotational position of the longitudinal member, the lock member comprising a pin, a member joined to the longitudinal member and a bias member operatively associated with the pin, the bias member biasing the pin to a first position that engages the pin with the member when the longitudinal member is moved from a predetermined rest position, and engagement of the pin with the member locks the rotational position of the longitudinal member; wherein at least one of said apertures is shaped differently than the other said apertures and each aperture and engagement surface is arranged adjacent the longitudinal member; the longitudinal member is rotatably positionable to arrange the spaced projections for engagement with a corresponding engagement surface to engage one or more of the plurality of weight plates; when the rotational position of the longitudinal member is locked by engagement of the pin with the member, a user is unable to rotate the longitudinal member around the longitudinal axis; and when the longitudinal member is moved to the predetermined rest position, the pin moves to a second position that disengages the pin from the member and allows the user to rotate the longitudinal member around the longitudinal axis.