Leg curl/leg extension weight training machine

An exercise machine for performing leg curl and leg extension movements, comprising:

• a frame configured to rest on an underlying surface;
• an upper leg-supporting assembly pivotally interconnected with the frame, the upper leg supporting assembly having a seat pad;
• a torso-supporting assembly pivotally interconnected with the frame and with the upper leg-supporting assembly, the torso-supporting assembly having a backrest pad;
• a movement arm unit pivotally attached to the frame at a first pivot axis, the movement arm unit including a leg curl movement arm and a leg extension movement arm;
• a resistance-imparting unit coupled with the leg curl movement arm and the leg extension movement arm;
• and
• a conversion mechanism interconnected with the frame and at least one of the torso-supporting assembly and the upper leg-supporting assembly, the conversion mechanism being configured to move the torso-supporting assembly and the upper leg-supporting assembly between a leg extension position, in which the seat pad and the backrest pad combine to form a backrest and seat for a seated exerciser, and a leg curl position, in which the seat pad and backrest pad combine to form a curl platform for a prone exerciser;
• wherein in the leg extension position, the first pivot axis is positioned in front of a front edge of the seat pad, and in the leg curl position, the first pivot is positioned above a plane defined by an upper surface of the seat pad.

An exercise machine for performing leg curl and leg extension movements, comprising:

• a frame configured to rest on an underlying surface;
• an upper leg-supporting assembly pivotally interconnected with the frame, the upper leg supporting assembly having a seat pad;
• a torso-supporting assembly pivotally interconnected with the frame and with the upper leg-supporting assembly, the torso-supporting assembly having a backrest pad;
• a movement arm assembly pivotally attached to the frame at a first pivot axis, the movement arm assembly including a leg curl movement arm and a leg extension movement arm;
• a resistance-imparting unit coupled with the leg curl movement arm and the leg extension movement arm;
• and
• a conversion mechanism interconnected with the frame and at least one of the torso-supporting assembly and the upper leg-supporting assembly, the conversion mechanism being configured to move the torso-supporting assembly and the upper leg-supporting assembly between a leg extension position, in which the seat pad and the backrest pad combine to form a backrest and seat for a seated exerciser, and a leg curl position, in which the seat pad and backrest pad combine to form a curl platform for a prone exerciser;
• wherein the first pivot axis is positioned between about 2 and 4 inches above a plane defined by the seat pad when the exercise machine is in the leg curl position, and wherein the second pivot axis is positioned between about 0.25 and 1 inches in front of a front edge of the seat pad when the exercise machine is in the leg extension position.

An exercise machine for performing leg curl and leg extension movements, comprising:

• a frame configured to rest on an underlying surface;
• an upper leg-supporting assembly pivotally interconnected with the frame, the upper leg supporting assembly having a seat pad;
• a torso-supporting assembly pivotally interconnected with the frame and with the upper leg-supporting assembly, the torso-supporting assembly having a backrest pad;
• a movement arm assembly pivotally attached to the frame at a first pivot axis, the movement arm assembly including a leg curl movement arm and a leg extension movement arm;
• a resistance-imparting unit coupled with the leg curl movement arm and the leg extension movement arm;
• and
• a conversion mechanism interconnected with the frame and the upper leg-supporting assembly, the conversion mechanism being configured to move the torso-supporting assembly and the upper leg-supporting assembly between a leg extension position, in which the seat pad and the backrest pad combine to form a backrest and seat for a seated exerciser, and a leg curl position, in which the seat pad and backrest pad combine to form a curl platform for a prone exerciser, the conversion mechanism comprising:
• a lifting member pivotally interconnected to the frame;
• a control link pivotally interconnected to the lifting member and to the upper leg-supporting assembly;
• a conversion pin attached to the lifting member;
• and
• a guide attached to the frame, the guide including a leg extension slot and a leg curl slot positioned such that, when the exercise machine is in the leg extension position, the conversion pin is received in the leg extension slot, and when the exercise machine is in the leg curl position, the conversion pin is in the leg curl slot.

An exercise machine for performing leg curl and leg extension movements, comprising:

• a frame configured to rest on an underlying surface;
• an upper leg-supporting assembly pivotally interconnected with the frame, the upper leg supporting assembly having a seat pad;
• a torso-supporting assembly pivotally interconnected with the frame and with the upper leg-supporting assembly, the torso-supporting assembly having a backrest pad;
• a leg curl assembly arm pivotally interconnected with the frame about a first pivot axis;
• a leg extension assembly arm pivotally interconnected with the frame about a second pivot axis;
• a resistance-imparting unit coupled with the leg curl movement arm and the leg extension movement arm;
• and
• a conversion mechanism interconnected with the frame and at least one of the torso-supporting assembly and the upper leg-supporting assembly, the conversion mechanism being configured to move the torso-supporting assembly and the upper leg-supporting assembly between a leg extension position, in which the seat pad and the backrest pad combine to form a backrest and seat for a seated exerciser, and in which the second pivot axis is positioned in front of a front edge of the seat pad, and a leg curl position, in which the seat pad and backrest pad combine to form a curl platform for a prone exerciser, and in which the first pivot is positioned above a plane defined by an upper surface of the seat pad;
• wherein in the leg curl position, the platform defined by the backrest pad and the seat pad forms an angle of between about 150 and 170 degrees;
• and wherein in the leg extension position, the backrest pad and the seat pad define an angle of between about 100 and 120 degrees.