Abdominal exerciser with rotatable seat and tandem pulley features

Abstract

An abdominal exerciser has base and back frames pivotally mounted for movement between upright and recumbent positions, and a seat frame with cushion rotatable on the base frame. A low friction journal between the base and seat frames supports a user's weight. The journal is about 30 to 42% the distance from a rear end of the cushion to its front end so the user's coccyx is vertically aligned with the journal. Arms at each side of the base frame have a pair of extensions connected to either the base or seat frame, each with a U-shaped handhold lying in a plane at an acute angle of about 30 to 80 degrees to the horizontal. A pair of single pulleys or a pair of tandem pulleys are mounted near the rear of the base frame and are engaged by sleeve-covered springs for biasing the back frame toward the upright position.

What is claimed is: 
     
         1 . An abdominal exercise device ( 10 ) comprising:
 a base frame ( 12 ) for lying in a horizontal plane on the floor, the base frame having a pair of side members ( 12   a ,  12   b ) and a cross member ( 12   c ) connected between the side members of the base frame;   a back frame ( 14 ) having a pair of side members ( 14   a ,  14   b ) pivotally mounted near respective rear ends of the respective side members ( 12   a ,  12   b ) of the base frame for movement between a forward upright position and a rearward recumbent position;   a plurality of back cushions ( 20 ) connected between and spaced along the side members ( 14   a ,  14   b ) of the back frame ( 14 );   an H-shaped seat frame ( 16 ) having front and rear members ( 16   a ,  16   b ) and a cross member ( 16   c ) connected between the front and rear members;   a seat cushion ( 30 ) fixed to the seat frame ( 16 ) and resting on the front, rear and cross members of the seat frame, the seat cushion having a front end and a rear end;   a low friction journal bushing ( 40 ) having a vertically extending bore and being connected to the cross member ( 12   c ,  16   c ) of one of the base and seat frames ( 12 ,  16 );   a journal post ( 42 ) connected to the cross member ( 12   c ,  16   c ) of the other of the base and seat frames ( 12 ,  16 ) and received for rotation in the low friction journal bushing ( 40 ) so that the seat cushion ( 30 ) may rotate with respect to the base frame ( 12 ), a support area of the cross member around the journal post and to which the journal post is connected, being in weight-bearing contact with the low friction journal bushing ( 40 ) for supporting the weight of a user sitting on the seat cushion, the location of the low friction journal bushing ( 40 ) and the journal post ( 42 ) received therein, being from about 30% to about 42% of the distance from the rear end of the seat cushion to the front end of the seat cushion so that when a user is sitting on the seat cushion ( 30 ) with the users back against the back cushions ( 20 ), the coccyx of the user is substantially vertically aligned with the low friction journal bushing ( 40 ) and journal post ( 42 ) received therein;   an arm ( 50 ) at each side of the base frame, each arm having a pair of extensions ( 50   a ,  50   b ) connected to one of the base frame and the seat frame, each arm including a U-shaped handhold ( 50   c ) lying in a plane that extends at an acute angle of about 30 degrees to about 80 degrees to the horizontal plane with the handholds ( 50   c ) of the arms ( 50 ) on opposite sides of the base frame extending outwardly from each other for increasing available room for a user sitting on the seat cushion, and access to the handholds by the user;   a pulley mounted for rotation at each side of the base frame near a rear end of the base frame;   a tension spring connected between the base frame and the back frame side members for biasing the back frame toward the forward upright position; and   a resilient sleeve covering each spring, each resilient sleeve engaged with one of the pulleys.   
     
     
         2 . The device of  claim 1 , wherein the side members ( 12   a ,  12   b ) of the base frame ( 12 ) each include a tubular side extension ( 12   d ,  12   e ), the extensions ( 50   a ,  50   b ) of each arm ( 50 ) being detachably attached to the tubular side extension on each respective side of the base frame ( 12 ) so that the arms are fixed to the base frame when the seat frame rotates. 
     
     
         3 . The device of  claim 1 , wherein the extensions ( 50   a ,  50   b ) of each arm ( 50 ) are detachably attached to ends of the respective front and rear members ( 16   a ,  16   b ) of the seat frame ( 16 ) on each respective side of the seat frame so that the arms rotate with the rotation of the seat frame. 
     
     
         4 . The device of  claim 1 , including a pair of tandem pulleys mounted for rotation at each side of the base frame and a tension spring connected between the base frame and the back frame side members each with a resilient sleeve covering each spring, engaged with each pulleys for biasing the back frame toward the forward upright position. 
     
     
         5 . The device of  claim 1 , wherein the handhold ( 50   c ) lying in a plane that extends at an acute angle of about 50 degrees to about 70 degrees to the horizontal plane. 
     
     
         6 . The device of  claim 1 , wherein the location of the low friction journal bushing ( 40 ) and the journal post ( 42 ) received therein, is from about 33% to about 39% of the distance from the rear end of the seat cushion to the front end of the seat cushion. 
     
     
         7 . The device of  claim 1 , wherein the rear member of the seat frame includes a seat frame extension ( 16   d ) that extends beyond the seat cushion ( 30 ), locking holes in the seat frame extension and in the base frame or in one arm extension, that are aligned when the seat cushion is rotation to a centered position, and a locking pin for insertion into the aligned locking holes for fixing the seat cushion in the center position. 
     
     
         8 . The device of  claim 1 , wherein the rear member of the seat frame includes a seat frame extension ( 16   d ) that extends beyond the seat cushion ( 30 ), locking holes in the seat frame extension and in the base frame or in one arm extension, that are aligned when the seat cushion is rotation to a centered position, and a locking pin for insertion into the aligned locking holes for fixing the seat cushion in the center position, the locking pin including an upper handle that is larger in at least one dimension than the locking holes, and a shaft that is smaller in diameter than the locking holes so that the shaft can extend into the aligned locking hole, the shaft including an annular groove near the upper handle. 
     
     
         9 . The device of  claim 1 , including an elastic band with at least one hook-and-loop covered strap extending from one edge of the band for engagement of the band onto the pulley and sleeve covered spring on each side of the base and back frames. 
     
     
         10 . An abdominal exerciser comprising: a base frame; a back frame pivotally mounted near a rear end of the base frame for movement between upright and recumbent positions; at least one back cushion connected to the back frame for supporting a user's back; a seat frame mounted for rotation on the base frame; a seat cushion fixed to the seat frame on which a user sits; a low friction journal bushing connected the base frame, a journal post connected to the seat frame and rotatable mounted in the bushing for rotation of the seat frame and cushion on the base frame; the low friction bushing supporting the weight of a user sitting on the seat cushion and the journal post being located at about 30% to about 42% of a distance from a rear end of the seat cushion to the front end of the seat cushion so that the coccyx of a user sitting on the seat cushion is substantially vertically aligned, with the bushing and post; an arm connected at each side of the base frame, each arm having a pair of extensions connected to the base frame; each arm having a U-shaped handhold lying in a plane extending at an acute angle of about 30 to about 80 degrees to a horizontal plane on which the base rests, a pair of pulleys mounted for rotation near a rear end of the base frame and on opposite sides of the base frame; a springs with a resilient sleeve thereover engaged to each pulley, the springs being connected between the base and back frames for biasing the back frame toward the upright position. 
     
     
         11 . The device of  claim 10 , wherein side members of the base frame include tubular side extensions, the extensions of each arm being detachably attached to the tubular side extension on each respective side of the base frame so that the arms are fixed to the base frame when the seat frame rotates, the handhold lying in a plane that extends at an acute angle of about 50 degrees to about 70 degrees to the horizontal plane, the location of the low friction journal bushing and the journal post received therein, being from about 33% to about 39% of the distance from the rear end of the seat cushion to the front end of the seat cushion, a rear member of the seat frame including a seat frame extension that extends beyond the seat cushion, locking holes in the seat frame extension and in the base frame or one of the arm extensions, that are aligned when the seat cushion is rotation to a centered position, and a locking pin for insertion into the aligned locking holes for fixing the seat cushion in the center position, the locking pin including an upper handle that is larger in at least one dimension than the locking holes, and a shaft that is smaller in diameter than the locking holes so that the shaft can extend into the aligned locking hole, the shaft including an annular groove near the upper handle. 
     
     
         12 . An abdominal exercise device comprising:
 a base frame for lying in a horizontal plane on the floor, the base frame having a pair of side members;   a back frame having a pair of side members pivotally mounted near respective rear ends of the side members of the base frame for movement between a forward upright position and a rearward recumbent position;   a plurality of back cushions connected between and spaced along the side members of the back frame;   a seat cushion mounted to the base frame;   an arm detachably connected to each side member of the base frame and on opposite sides of the seat cushion;   a pair of side-by-side tandem pulleys mounted for rotation at each side member of the base frame near a rear end of the base frame;   a pair of tension springs connected between the base frame and the back frame side members on each side of the base and back frames for biasing the back frame toward the forward upright position; and   a resilient sleeve covering each spring, each resilient sleeve engaged with one of the pulleys.   
     
     
         13 . The device of  claim 12 , wherein the side members ( 12   a ,  12   b ) of the base frame ( 12 ) each include a tubular side extension ( 12   d ,  12   e ), the extensions ( 50   a ,  50   b ) of each arm ( 50 ) being detachably attached to the tubular side extension on each respective side of the base frame ( 12 ) so that the arms are fixed to the base frame when the seat frame rotates. 
     
     
         14 . The device of  claim 12 , wherein the extensions ( 50   a ,  50   b ) of each arm ( 50 ) are detachably attached to ends of the respective front and rear members ( 16   a ,  16   b ) of the seat frame ( 16 ) on each respective side of the seat frame so that the arms rotate with the rotation of the seat frame. 
     
     
         15 . The device of  claim 12 , including a pair of tandem pulleys mounted for rotation at each side of the base frame and a tension spring connected between the base frame and the back frame side members each with a resilient sleeve covering each spring, engaged with each pulleys for biasing the back frame toward the forward upright position. 
     
     
         16 . The device of  claim 12 , wherein the handhold ( 50   c ) lying in a plane that extends at an acute angle of about 50 degrees to about 70 degrees to the horizontal plane. 
     
     
         17 . The device of  claim 12 , wherein the location of the low friction journal bushing and the journal post received therein, is from about 33% to about 39% of the distance from the rear end of the seat cushion to the front end of the seat cushion. 
     
     
         18 . The device of  claim 12 , wherein the rear member of the seat frame includes a seat frame extension that extends beyond the seat cushion, locking holes in the seat frame extension and in the base frame or in one of the arm extension, that are aligned when the seat cushion is rotation to a centered position, and a locking pin for insertion into the aligned locking holes for fixing the seat cushion in the center position. 
     
     
         19 . The device of  claim 12 , wherein the rear member of the seat frame includes a seat frame extension that extends beyond the seat cushion, locking holes in the seat frame extension and in the base frame or in one of the arm extensions, that are aligned when the seat cushion is rotation to a centered position, and a locking pin for insertion into the aligned locking holes for fixing the seat cushion in the center position, the locking pin including an upper handle that is larger in at least one dimension than the locking holes, and a shaft that is smaller in diameter than the locking holes so that the shaft can extend into the aligned locking hole, the shaft including an annular groove near the upper handle. 
     
     
         20 . The device of  claim 12 , including an elastic band with at least one hook-and-loop covered strap extending from one edge of the band for engagement of the band onto the pulley and sleeve covered spring on each side of the base and back frames.