Exercise machine with variable resistance system

An exercise machine, comprising:

• a frame having a first end, a second end, and a rail;
• a carriage movably positioned upon the rail, wherein the carriage is movable between the first end and the second end, and wherein the carriage includes an upper surface adapted to receive and support an exerciser;
• a main shaft rotatably connected to the frame;
• a main connector connected between the main shaft and the carriage;
• a plurality of resistance assemblies, wherein each of the plurality of resistance assemblies includes a bias member adapted to exert a resistance force against rotation of the main shaft in a first rotational direction, wherein each of the plurality of resistance assemblies is selectively rotationally locked with the main shaft or rotationally unlocked with the main shaft;
• and
• a plurality of actuation assemblies, wherein each of the plurality of actuation assemblies are adapted for selectively rotationally locking and unlocking one of the plurality of resistance assemblies with respect to the main shaft, wherein the plurality of resistance assemblies apply a total level of rotational resistance against the main shaft based on which of the plurality of resistance assemblies are rotationally locked with the main shaft by the plurality of actuation assemblies;
• wherein each of the plurality of resistance assemblies includes a clutch, wherein each of the plurality of resistance assemblies is selectively rotationally locked or unlocked with the main shaft by the clutch to adjust the total level of rotational resistance against the main shaft;
• wherein each of the plurality of actuation assemblies includes a shift member to connect to the clutch for engaging or disengaging the clutch to selectively rotationally lock or unlock each of the plurality of resistance assemblies with respect to the main shaft;
• wherein each of the plurality of resistance assemblies comprises a pulley rotatably positioned upon the main shaft and wherein the pulley is connected to the bias member;
• wherein the clutch selectively engages the pulley to selectively rotationally lock or unlock the pulley with respect to the main shaft;
• wherein the pulley is connected to the main shaft in a non-rotating manner with respect to the main shaft when the pulley is in a locked state with respect to the main shaft, and wherein the pulley is connected to the main shaft in a rotating manner so as to allow for free rotation of the pulley with respect to the main shaft when the pulley is in an unlocked state with respect to the main shaft.

An exercise machine, comprising:

• a frame having a first end, a second end, and a rail extending between the first end and the second end of the frame;
• a carriage movably positioned upon the rail, wherein the carriage is movable between the first end and the second end in a reciprocating manner, and wherein the carriage includes an upper surface adapted to receive and support an exerciser;
• a main shaft rotatably connected to the frame;
• a main connector connected between the main shaft and the carriage;
• a plurality of resistance assemblies, wherein each of the plurality of resistance assemblies includes a bias member adapted to exert a resistance force against rotation of the main shaft in a first rotational direction, wherein each of the plurality of resistance assemblies is selectively rotationally locked with the main shaft or rotationally unlocked with the main shaft;
• and
• a plurality of actuation assemblies, wherein each of the plurality of actuation assemblies are adapted for selectively rotationally locking and unlocking one of the plurality of resistance assemblies with respect to the main shaft, wherein the plurality of resistance assemblies apply a total level of rotational resistance against the main shaft based on which of the plurality of resistance assemblies are rotationally locked with the main shaft by the plurality of actuation assemblies;
• wherein each of the plurality of resistance assemblies includes a clutch, wherein each of the plurality of resistance assemblies is selectively rotationally locked or unlocked with the main shaft by the clutch to adjust the total level of rotational resistance against the main shaft;
• wherein each of the plurality of actuation assemblies includes a shift member to connect to the clutch for engaging or disengaging the clutch to selectively rotationally lock or unlock each of the plurality of resistance assemblies with respect to the main shaft;
• wherein each of the plurality of resistance assemblies comprises a pulley rotatably positioned upon the main shaft and wherein the pulley is connected to the bias member;
• wherein the clutch selectively engages the pulley to selectively rotationally lock or unlock the pulley with respect to the main shaft;
• wherein the pulley is connected to the main shaft in a non-rotating manner with respect to the main shaft when the pulley is in a locked state with respect to the main shaft, and wherein the pulley is connected to the main shaft in a rotating manner so as to allow for free rotation of the pulley with respect to the main shaft when the pulley is in an unlocked state with respect to the main shaft;
• wherein the clutch is comprised of a non-slip clutch;
• wherein each of the plurality of actuation assemblies is comprised of a motor or an electric actuator.