1. Field of the Invention
This invention relates to an exercise apparatus that operates in both an isotonic mode and an isometric mode. In the isotonic mode the apparatus provides preset resistance in a controlled range of motion.
2. Description of the Prior Art
Many prior art devices are available for practicing resistance exercises, including such devices as barbells and weight machines in which the exerciser performs a variety of constrained motions by pushing or pulling on bars, handles attached to cables, or similar structures. In other types of exercising devices, the resistance is provided by springs, or hydraulic or pneumatic pressure. Still another approach is to pull a rope through a device which applies frictional resistance to the motion of the rope. Exercises performed with each of the above devices are referred to as isotonic because they are performed over a range of motion.
Another type of exercise where force is applied but no motion occurs, is referred to as isometric. Examples of isometric exercises include standing on one end of a rope and pulling on the other end, or grasping a rope in both hands and pulling the rope. When performing this type of isometric exercise, a tension measuring device may be attached to the rope to provide an indication of the effort exerted by the exerciser.
The usefulness of a particular exercise device is determined among other things by the variety of exercises that can be performed, the range of resistance that can be applied, mode of exercise (i.e. isometric or isotonic), cost, control of speed of motion, durability, convenience of location and overall weight.
It will be obvious in light of the teachings of this specification that this invention combines all of these factors to provide a significant improvement over prior art exercise devices.