| 摘要 |
For the purpose of strengthening the abdominal muscles and the digestive tract, an abdomen training unit comprises a potshaped base element and a similarly pot-shaped actuating part which does not rotate but moves up and down in relation to the base element; the unit is secured to the abdomen by means of a body belt, a bearing surface resting upon the abdomen in such a manner that a compression springs clamped between the base element and the actuating part, is expanded when the abdomen is drawn in and is compressed when the abdomen is arched out; the compression spring bears against the base element through a control element which can be removed therefrom after the manner of a bayonet fastening, the control element carries cams which, upon rotation of the control element, follow axial thrust surfaces, thus displacing the control element axially for the purpose of adjusting the preload force of the compression spring; the diameter of the control element is greater than that of the compression spring, so that the latter can be changed, through the control element bearing aperture, for the purpose of varying the hardness of the spring. |
