Abstract: A dual function exercise machine, enabling unilateral and bilateral exercise of a limb, includes a pair of lever arms pivotally mounted adjacent to each other on a frame. Each lever arm is slidably mounted through a separate linear bearing sleeve at a point remote from the pivot point and is associated with a separate and independent stack of weights. Each weight stack is slidably mounted on guide bars of the frame. Each sleeve is pivotally connected to a selector bar which is adapted to connect a number of weights to the sleeve to provide resistance during either unilateral or bilateral exercise of a limb. In this manner, one or both corresponding limbs may be exercised with the same or different number of weights connected to each lever arm.

Abstract: A variable resistance lifting mechanism for increasing the resistive force during an exercise stroke includes a lever arm pivotally attached to a frame at one end and slidably mounted through a linear bearing sleeve at a position remote from the pivot point. In one embodiment, the linear bearing sleeve is connected by a clevis pin to a housing slidable in a linear manner on guide bars. A bar secured to the housing is adapted to be attached to a predetermined number of weights. The weights are also slidable in a linear manner on the guide bars. In a second embodiment, the linear bearing sleeve is pivotally connected by the clevis pin directly to the bar adapted to the attached to the predetermined number of weights.