Device for effecting resistance

A device for effecting resistance, said device being incorporated into an exercise or rehabilitation machine such that a magnetic resistance of a closed loop magnetic field effect is brought about at such time when the exercise or rehabilitation machine is in operation, said device comprising an excited magnetic cylinder, an excited magnetic coil, a rotary cylinder, and two support frames, said excited magnetic coil being disposed in said excited magnetic cylinder which is provided in the fringe thereof with an annular wavy interstice having two sides acting as N/S poles for bringing about magnetic field, said two sides provided with a plurality of ridges, with each having a projection serving as a magnetic pole induction area, said rotary cylinder provided with a round slot having an annular wall contiguous to said wavy interstice, said excited magnetic cylinder being provided in two sides with a fixed shaft being located in a locating hole of said support frames, said excited magnetic cylinder bringing about a closed loop magnetic field at the time when said excited magnetic coil is connected to a power source, thereby causing a magnetic line to be guided via said projections of said ridges, so as to bring about a magnetic resistance action causing said excited magnetic cylinder and said rotary cylinder to attract each other;

• wherein said rotary cylinder is provided at one end thereof with said round slot for fitting over said annular wavy interstice of said excited magnetic cylinder such that an appropriate gap is formed, said round slot being provided in the fringe with a plurality of ribs arranged equidistantly, said rotary cylinder being provided at other end thereof with a link shaft for linking said device with the exercise machine, said link shaft provided along the axial direction thereof with a through hole in communication with said round slot, said through hole provided at two ends thereof with a slot for disposing a bearing to facilitate said through hole to be fitted over said fixed shaft of said excited magnetic cylinder such that said rotary cylinder turns freely on said fixed shaft of said excited magnetic cylinder;
• wherein said excited magnetic cylinder is formed of a toothed disk and a toothed cylinder, said toothed disk being provided in the axial direction thereof with a fixed shaft, a shaft seat and a protruded ring which are located between said toothed disk and said fixed shaft, said toothed disk being provided in the fringe with a plurality of teeth whereby said teeth are provided with a projected step and are further provided in the side of tooth edge thereof with an inclined plane serving as a current guiding surface, said shaft seat and said fixed shaft being provided with an L-shaped through hole located therebetween for receiving a wire of said excited magnetic coil such that said wire is connected to a power source, said toothed cylinder being provided at one end with a plurality of ridges whereby said ridges are provided with a projection and are further provided in the side of tooth edge thereof with a slanted surface, said toothed cylinder being provided at other end with an axial hole which is fitted over said protruded ring of said toothed disk, said toothed disk and said toothed cylinder enabling the peripheral edge of said excited magnetic cylinder to have said annular wavy interstice.