Machine for gymnastic exercises, particularly for exercising the abdominal muscles

Abstract

A machine for gymnastic exercises, particularly for exercising the abdominal muscles, comprising a supporting footing which is associated with a rolling track for a cradle-like structure which is integral with a seat provided with a sitting portion that is at least partly movable with respect to a backrest thereof; elements are provided for tilting the cradle-like structure which are connected kinematically to the sitting portion for the rolling of the cradle-like structure on the rolling track, as a consequence of the movement of the legs toward the upper body of the user, between an inactive position, in which the backrest is substantially oriented vertically, and a maximum effort position, in which the backrest is substantially reclined backwards, and vice versa.

What is claimed is:  
     
         1 . A machine for gymnastic exercises, particularly for exercising the abdominal muscles, further comprising a supporting footing which is associated with a rolling track for a cradle-like structure which is integral with a seat provided with a sitting portion that is at least partly movable with respect to the backrest of said seat as a consequence of the movement of the legs toward the upper body of a user who is seated on said seat while keeping said upper body resting on said backrest, means also being provided for the tilting of said cradle-like structure, which are connected kinematically to said sitting portion for the rolling of said cradle-like structure on said rolling track as a consequence of the movement of said legs toward said upper body, between an inactive position, in which said backrest is substantially oriented vertically, and a maximum effort position, in which said backrest is substantially reclined backwards, and vice versa. 
     
     
         2 . The machine according to  claim 1 , further comprising means for adjusting the inclination of said rolling track in order to vary the extent of the effort required to perform the gymnastic exercise. 
     
     
         3 . The machine according to  claim 1 , said sitting portion comprises a first portion which is integral with and adjacent to said backrest and a second portion which is articulated with respect to said first portion by way of two first linkages which are pivoted, with their ends, laterally to said portions of said sitting portion, said second portion being provided with a fixing belt which is adapted to be fastened around the legs of said user so as to allow the movement of said second portion with respect to said first portion. 
     
     
         4 . The machine according to  claim 1 , wherein said tilting means comprise a second linkage which is pivoted at its ends, respectively, to said second portion of said sitting portion and to an end portion of a first lever, said first lever being pivoted, at a central part thereof, to said cradle-like structure and being pivoted, at its other end portion, to said seat substantially at the intersection defined between said backrest and said sitting portion, a third linkage being also provided which is pivoted, at its ends, respectively to said other end portion of said first lever and to an end portion of a second lever, said second lever being pivoted, at a central part thereof, to said cradle-like structure at a central portion of said backrest and being pivoted, at its other end portion, to a fourth linkage, which is pivoted, at ends thereof, respectively to said second lever and to said rolling track. 
     
     
         5 . The machine according to  claim 1 , said rolling track comprises two straight guides which are arranged below said cradle-like structure at two curved bars which define said cradle-like structure. 
     
     
         6 . The machine according to  claim 5 , further comprising means for centering said curved bars on said straight guides, said means consisting of centering holes and pins which are defined on the mutually facing surfaces of said curved bars and of said straight guides and of shoulders which are defined laterally with respect to said straight guides. 
     
     
         7 . The machine according to  claim 1 , further comprising grip handles which are associated with said seat proximate to the upper part of said backrest. 
     
     
         8 . The machine according to  claim 2 , wherein said adjustment means comprise a control lever which is pivoted to said supporting footing and is associated with a fifth linkage which is pivoted to a crank which is integral in rotation with an actuation shaft of pushers arranged below said rolling track at an end portion thereof so as to be able to lift it by a vertical extent that is proportional to the rotation of said control lever, said rolling track being pivoted to said supporting footing at its other end portion. 
     
     
         9 . The machine according to  claim 8 , wherein said control lever is movable between a plurality of positions, which correspond to different inclinations of said rolling track so as to vary the extent of the effort required to perform the gymnastic exercise. 
     
     
         10 . The machine according to  claim 2 , wherein all the pivoting axes and all the pivoting points of said tilting means and of said adjustment means are oriented along directions which are parallel to the oscillation axis of said cradle-like structure with respect to said rolling track.