Balanced magnetic brake assembly for exercise cycling apparatus

Abstract

A brake assembly for exercise cycling apparatus comprises rotor means ( 2 ) with at least one pair of magnetic elements ( 4, 4′ ) adapted to be rotated about a longitudinal axis (X) by a user who applies a driving torque thereon, stator means ( 3 ) adapted to cooperate with the at least one pair of magnetic elements ( 4, 4′ ) to generate a resistance torque adapted to oppose the above driving torque, guide means ( 7 ) associated to the rotor means ( 2 ) to cause translation of the magnet elements ( 4, 4′ ) along respective directions (d, d′) having at least one radial component to cause variation of the resistance torque proportionally to the driving torque. The magnetic elements ( 4, 4′ ) are reciprocally coupled to make the displacement thereof along directions (d, d′) mutually dependent and with substantially the same length (l, l′).

1 . A brake assembly for an exercise cycling apparatus, comprising:
 rotor means ( 2 ) with at least one pair of magnetic elements ( 4 ,  4 ′) designed to be rotary driven about a longitudinal axis (X) by a user exerting a driving torque thereon,   stator means ( 3 ) designed to cooperate with said at least one pair of magnetic elements ( 4 ,  4 ′) to generate a resistance torque opposing said driving torque;   guide means ( 7 ) associated to said rotor means ( 2 ), to allow translation of said magnetic elements ( 4 ,  4 ′) along respective directions (d, d′) having at least one radial component, to cause said resistance torque to change proportionally to said driving torque,   characterized in that said magnetic elements ( 4 ,  4 ′) are reciprocally coupled o male their displacements along said directions (d, d′) mutually dependent and with substantially the same length (l, l′).   
     
     
         2 . Assembly as claimed in  claim 1 , characterized in that said magnetic elements ( 4 ,  4 ′) are reciprocally coupled by a kinematic chain ( 8 ). 
     
     
         3 . Assembly as claimed in  claim 2 , characterized in that said kinematic chain ( 8 ) is of the closed type. 
     
     
         4 . Assembly as claimed in  claim 2 , characterized in that said kinematic chain ( 8 ) comprises at least one prismatic pair ( 14 ,  14 ′). 
     
     
         5 . Assembly as claimed in  claim 4 , characterized in that said at least one prismatic pair ( 14 ,  14 ′) comprises a pair of substantially radial slots ( 16 ,  16 ′) formed in a substantially rigid plate ( 17 ,  17 ) integral with said rotor means ( 2 ), and pins ( 15 ,  15 ′) associated to said magnetic elements ( 4 ,  4 ′) slidably guided within said slots ( 16 ,  16 ′). 
     
     
         6 . Assembly as claimed in  claim 5 , characterized in that said plate ( 17 ) is rotatably mounted to a shaft ( 5 ) defining said longitudinal axis (X), to rotate freely about said axis (X) integrally with said magnetic elements ( 4 ,  4 ′). 
     
     
         7 . Assembly as claimed in  claim 6 , characterized in that said slots ( 16 ,  16 ′) extend along directions (D, D′) are substantially parallel to each other and inclined with respect to said translation directions (d, d′) of said magnetic elements ( 4 ,  4 ′). 
     
     
         8 . Assembly as claimed in  claim 7 , characterized in that said slots ( 16 ,  16 ′) are formed in substantially radial appendices ( 18 ,  18 ′) of said plate ( 17 ) which extend from a central portion ( 19 ). 
     
     
         9 . Assembly as claimed in  claim 1 , wherein said rotor means ( 2 ) include a support disc ( 11 ) which is rotatably mounted to said shaft ( 5 ) characterized in that said guide means ( 7 ) include at least one pair of arms ( 12 ,  12 ′) pivoted on said disc ( 11 ) and rigidly coupled to said magnetic elements ( 4 ,  4 ′). 
     
     
         10 . Assembly as claimed in  claim 9 , characterized in that each of said arms ( 12 ,  12 ′) pivots on said disk ( 11 ) at one longitudinal end ( 13 ,  13 ′) for rotating radially outwards in response to the centrifugal force induced by said driving torque. 
     
     
         11 . Assembly as claimed in  claim 9 , characterized in that said guide means ( 7 ) further include elastic means ( 20 ,  20 ′), acting on said arms ( 12 ,  12 ′) to counteract the centrifugal force and cause opening thereof in response to a predetermined value of such force. 
     
     
         12 . An exercise cycling apparatus comprising a support frame (B) for the rear wheel of a bicycle, a roller (C) designed to contact the bicycle wheel to be rotated by a user through the application of a driving torque, braking means to generate a resistance torque adapted to oppose said user-applied torque, characterized in that said braking means include a brake assembly as claimed in one or more of the preceding claims.