Exercise Apparatus with Variable Mode Hydraulic Cylinder
US Patent: 7,762,934
This patent discloses a hydraulic cylinder for use in exercise machines to deliver a controllable fast acting force. The invention uses a hydraulic cylinder with features that allow high acceleration rates, rapid changes of force level and direction, and positive force limitation.
Method and Apparatus for Physical Fitness Training
US Patent: 7,547,269
This patent discloses an improved method and apparatus for physical strength, agility and endurance training uses fluid jet reaction forces to train and strengthen muscles.