Gymnastic machine

Abstract

Gymnastic machine ( 1 ) for performing walking or running exercises along a given direction (D) includes a frame ( 10 ) and an endless belt ( 20 ) wound in a loop on a pair of rollers ( 30 ) carried by the frame ( 10 ) transversely to the given direction (D), with a tensioning device ( 40 ) provided in association with at least a first of the rollers ( 30 ) to maintain the belt ( 20 ) longitudinally tensioned in a uniform manner and with a centering device ( 60 ) provided to maintain the belt ( 20 ) disposed substantially equidistant from first lateral end portions ( 32 ) of each roller ( 30 ).

1 . A gymnastic machine ( 1 ) for performing walking or running exercises along a direction (D) of feed and comprising a frame ( 10 ) and an endless belt ( 20 ) wound in a loop on a pair of rollers ( 30 ) carried by said frame ( 10 ) transversely to said direction (D) of feed, characterized by comprising centering means ( 60 ) of geometrical type, suitable to maintain said belt ( 20 ) disposed substantially equidistant from first lateral end portions ( 32 ) of each said roller ( 30 ).  
   
   
       2 . A machine according to  claim 1 , characterized by comprising tensioning means ( 40 ) carried by said frame ( 10 ) in association with at least a first of said rollers ( 30 ) to maintain said belt ( 20 ) longitudinally tensioned in a uniform manner; said centering means ( 60 ) being designed to cooperate with said tensioning means ( 40 ) in order to determine localised variations of the distribution of the tension of said endless belt ( 20 ) to condition transverse positioning thereof.  
   
   
       3 . A machine according to  claim 2 , characterized in that said centering means ( 60 ) are shape centering means.  
   
   
       4 . A machine according to  claim 3 , characterized in that said centering means comprise said first lateral end portions ( 32 ) of at least one said roller ( 30 ).  
   
   
       5 . A machine according to  claim 4 , characterized in that each said first lateral end portion ( 32 ) is shaped for shape interaction with said endless belt ( 20 ) at respective second lateral portions ( 26 ).  
   
   
       6 . A machine according to  claim 5 , characterized in that each said first lateral end portion ( 32 ) presents a longitudinal section shaped so as to determine, in use, a variation of the direction of the resultant of the tension applied laterally to said belt ( 20 ) at the relative said second lateral portion ( 26 ), in order to produce a transverse thrust on said belt ( 20 ) of a level proportional to a degree of overlapping of said first lateral end portion ( 32 ) by said second lateral portion ( 26 ) of said belt ( 20 ).  
   
   
       7 . A machine according to  claim 1 , characterized in that each said first lateral end portion ( 32 ) is delimited by a substantially arched longitudinal section.  
   
   
       8 . A machine according to  claim 7 , characterized in that each said first lateral end portion ( 32 ) presents a radius (R) of curvature between 0.7 and 0.9 times a width of said endless belt ( 20 ).  
   
   
       9 . A machine according to  claim 7 , characterized in that each said first lateral end portion ( 32 ) extends transversely for a length between 0.06 and 0.1 times the width of said endless belt ( 20 ).  
   
   
       10 . A roller ( 30 ) for a gymnastic machine ( 1 ) for performing walking or running exercises along a direction (D) of feed and described with reference to at least one of the preceding claims, characterized by comprising respective said first lateral end portions ( 32 ) presenting a longitudinal section shaped so as to determine, in use, a variation of the direction of the resultant of the tension applied laterally to said endless belt ( 20 ) at respective said second lateral portions ( 26 ), in order to produce a transverse thrust of a level proportional to a degree of overlapping of said first lateral end portions ( 32 ) by said second lateral portions ( 26 ) of said belt ( 20 )  
   
   
       11 . A roller according to  claim 10 , characterized in that the first lateral end portions ( 32 ) are delimited by a substantially arched longitudinal section.  
   
   
       12 . A roller according to  claim 11 , characterized in that each said first lateral end portion ( 32 ) presents a radius of curvature between 0.7 and 0.9 times a width of said endless belt ( 20 ).  
   
   
       13 . A roller according to  claim 11 , characterized in that each said first lateral end portion ( 32 ) extends transversely for a length between 0.0 and 0.1 times the width of said endless belt ( 20 ).  
   
   
       14 . An annular endless belt for a gymnastic machine for performing walking or running exercises along a direction (D) of feed and described with reference to  claim 1 , characterized by presenting a cross section comprising a rectilinear central portion ( 28 ) delimited by said second lateral portions ( 26 ) shaped for shape coupling with said first lateral end portions ( 32 ) of at least one said roller ( 30 ).  
   
   
       15 . A belt according to  claim 14 , characterized in that said second lateral portions ( 26 ) have an arched cross section for shape coupling with said first lateral end portions ( 32 ) of at least one said roller ( 30 ) when, in use, said belt ( 20 ) is positioned equidistant from said first lateral end portions ( 32 ) of at least one said roller ( 30 ).  
   
   
       16 . A belt according to  claim 15 , characterized in that at least said second lateral portions ( 26 ) are produced with elastic material for shape coupling with said first lateral end portions ( 32 ) of at least one said roller ( 30 )  
   
   
       17 . A belt according to  claim 14 , characterized by comprising a plurality of panels ( 29 ) substantially identical to one another, each of which is delimited by a first side (A) and by a second side (B) transverse to said direction (D) of feed and by two lateral sides (L).  
   
   
       18 . A method for producing an annular endless belt for a gymnastic machine for performing walking or running exercises along a given direction and described with reference to  claim 14 , characterized by comprising a step of cutting a plurality of panels ( 29 ) substantially rectangular in shape and substantially identical to one another and delimited by a pair of said lateral sides (L) substantially parallel to each other and by a said first side (A) and a said second side (B) transverse to said direction (D) of feed; a step of stitching said panels ( 20 ) to one another to couple one said first side (A) and one said second side (B) so as to determine a curvature of the lateral edge of said belt ( 20 ) which corresponds to a shape coupling of said second lateral portions ( 26 ) of said belt with arched said first lateral end portions ( 32 ) of said rollers ( 30 ).  
   
   
       19 . A method according to  claim 18 , characterized in that said first side (A) is substantially rectilinear; said second side (B) presenting a substantially rectilinear second central portion (C) delimited by two arched edges (E) symmetrical with each other, so as to create a curvature of the lateral edge of said belt ( 20 ).  
   
   
       20 . A method according to  claim 19 , characterized by comprising the step of cutting each said panel ( 29 ) with the respective said third lateral sides (L) inclined with respect to each other so that the linear extension of each said first side (A) approximates, but is slightly less than, the linear extension of the respective second side (B) to which it is coupled.