Body exerciser

Abstract

A body exerciser includes a seat member supported by a leg post, a crank shaft mounted on two bearing members that are disposed rearwardly of the seat member so as to be rotatable clockwise and counterclockwise about an axis, a backrest member secured to the crank shart for swinging clockwise to a bending position or counterclockwise to a straightening position, and a deformable resisting member connected to a crank web on the crank shaft and to an anchored member. The resisting member is tensioned at the bending and straightening positions, thereby generating a biasing action to resist movement of the backrest member.

I claim:  
     
         1 . A body exerciser comprising: 
 a leg post having bottom and top ends opposite to each other in an upright direction, said bottom end defining a horizontal plane and adapted to be placed on the ground;    a seat member disposed or said top end and having front and rear sides opposite to each other in a longitudinal direction transverse to the upright direction;    a pair of bearing members disposed rearwardly of said rear side of said seat member and opposite to each other in a transverse direction relative to both of the upright and longitudinal directions, each of said bearing members being spaced apart from the horizontal plane in the upright direction with a first height;    a crank shaft with two ends mounted on said bearing members respectively to be rotatable in clockwise and counterclockwise directions about a rotating axis in the transverse direction;    a backrest member having a proximate end secured to said crank shaft at a first position and rotatable together with said crank shaft so as to permit said backrest member to swing clockwise to a bending position or counterclockwise to a straightening position, and a distal end opposite to said proximate end in a radial direction relative to the rotating axis such that said distal end is closer to and is remote from said seat member when said backrest member is in the bending and straightening positions, respectively;    a crank web disposed on said crank shaft at a second position which is angularly spaced apart from and which lags behind the first position when said crank shaft rotates in the clockwise direction, said crank web extending radially from said crank shaft and terminating at a pivoting end;    an anchored member disposed rearwardly of and spaced apart from said crank shaft in the longitudinal direction, and further spaced apart from the horizontal plane in the upright direction with a second height which is less than the first height; and    a resisting member made from a deformable material, and including an anchoring end which is anchored to said anchored member, and a pivoted end which is pivotally mounted on said pivoting end, such that said resisting member will be tensioned at both the bending and straightening positions, and as a result of being tensioned, said resisting member will generate a biasing action to resist movement of said backrest member to either of the bending and straightening positions.    
     
     
         2 . The body exerciser of  claim 1 , further comprising an elongated frame having front and rear portions which are disposed opposite to each other in the longitudinal direction and which are connected to said bottom end of said leg post and said anchored member, respectively.  
     
     
         3 . The body exerciser of  claim 2 , wherein said leg post includes two front legs spaced apart from each other in the transverse direction, and two rear legs spaced apart from each other in the transverse direction and disposed between said front legs and said front portion of said elongated frame, said rear legs respectively having two upper ends spaced apart from the horizontal plane in the upright direction with the first height so as to be mounted respectively with said bearing members, said body exerciser further comprising a middle axle which extends along the rotating axis to interconnect said bearing members, said crank shaft being tubular and being sleeved rotatably on said middle axle and said bearing members.  
     
     
         4 . The body exerciser of  claim 3 , further comprising a pair of pad members sleeved on said ends of said crank shaft, respectively.  
     
     
         5 . The body exerciser of  claim 3 , wherein said anchored member includes a positioning wall secured on said rear portion of said elongated frame, a movable portion disposed movably relative to said positioning wall in the longitudinal direction and engaging said anchoring end of said resisting member to adjust the biasing force of said resisting member, a fastening portion disposed to fasten said movable portion relative to said positioning wall in the longitudinal direction, and a guiding portion disposed to guide movement of said movable portion in the longitudinal direction.  
     
     
         6 . The body exerciser of  claim 5 , wherein said fastening portion includes a threaded bolt secured on and extending rearwardly from said movable portion to terminate at a projecting end which passes through said positioning wall, and a screw nut engaging threadedly said projecting end so as to fasten said movable portion on said positioning wall.  
     
     
         7 . The body exerciser of  claim 6 , wherein said guiding portion includes a keyway disposed forwardly of said positioning wall and extending in the longitudinal direction, and a key disposed on said movable member and engaging movably said keyway so as to guide movement of said movable portion.  
     
     
         8 . The body exerciser of  claim 1 , further comprising a handle secured on said distal end of said backrest member, and provided with a pair of handgrips that extend forwardly of said distal end.