Sit-Up Board

Abstract

Disclosed herein is a sit-up board. The sit-up board includes a first board ( 110 ), a second board ( 120 ), and a guy cable ( 160 ). At least one tension spring is provided on a lower surface of the first board. At least one extension cable, which is coupled to an end of the tension spring and extends the tension spring, is drawn to the upper surface of the first board along a plurality of guide units provided on the lower surface of the first board. The second board is coupled to the first board via a hinge unit in such a way as to rotate downwards, with a foot support being detachably mounted to the second board. The guy cable passes through ends of the first and second boards, and supports the first and second boards at a predetermined angle. This invention facilitates a wide variety of exercises.

1 . A sit-up board, comprising: 
 a first board, comprising: at least one elastic member provided on a lower surface of the first board; at least one extension cable coupled to an end of the elastic member, and extending the elastic member; and a plurality of guide units provided on the lower surface of the first board, so that the extension cable is drawn to an upper surface of the first board along the guide units;    a second board coupled to the first board via a hinge unit in such a way as to rotate downwards, with a foot support being detachably mounted to the second board; and    a guy cable passing through ends of the first and second boards, and supporting the first and second boards at a predetermined angle.    
     
     
         2 . The sit-up board according to  claim 1 , wherein the elastic member comprises a tension spring.  
     
     
         3 . The sit-up board according to  claim 1 , wherein both ends of the guy cable are held by a fastening button, and an insertion hole is formed in a central portion of the fastening button so that a stop protrusion provided at each of the ends of the guy cable is inserted into the insertion hole, the insertion hole having a cross shape and being formed such that a central portion of the insertion hole is wide to allow the stop protrusion to be easily inserted into the insertion hole, and a side portion of the insertion hole is narrow to secure the inserted stop protrusion therein, the stop protrusion being provided at two or more places on each of the ends of the guy cable.  
     
     
         4 . The sit-up board according to  claim 1 , wherein the extension cable of the first board is provided with at least one stop protrusion such that a handle is detachably coupled to the extension cable, and an insertion hole is formed at a predetermined position on the handle such that the stop protrusion is inserted into the insertion hole, with a seat being provided at a predetermined position on the insertion hole such that the stop protrusion is seated in and locked to the seat.  
     
     
         5 . The sit-up board according to  claim 1 , wherein the second board comprises: at least one tension spring provided on a lower surface of the second board; an extension cable coupled to a lower end of the tension spring, and extending the tension spring; and a plurality of guide units provided on the lower surface of the second board, so that the extension cable is drawn to an upper surface of the second board along the guide units, and is fastened to the foot support.  
     
     
         6 . The sit-up board according to  claim 1 , wherein the foot support has a circular shape, and comprises: a first fastening part jointed by a hinge shaft; and a second fastening part comprising: a rod-shaped locking lug; and a lug holder to prevent upward movement of the locking lug when the locking lug has been seated in the lug holder, wherein an insertion hole is provided at a predetermined position on the first fastening part such that a head of a fastening bolt of the second board or the stop protrusion provided on each of the ends of the extension cable of the second board is inserted into the insertion hole, the insertion hole having a cross shape and being formed such that a central portion thereof is wide to allow the head of the fastening bolt or the stop protrusion to be easily inserted into the insertion hole, and a side portion is narrow to allow the inserted head of the fastening bolt or the inserted stop protrusion to be seated in and locked to the insertion hole.  
     
     
         7 . The sit-up board according to  claim 1 , wherein the foot support comprises: a body; and hook and pile pieces of a Velcro provided on opposite ends of the body, wherein an insertion hole is provided at a predetermined position on the body such that a head of a fastening bolt of the second board or the stop protrusion provided on each of the ends of the extension cable of the second board is inserted into the insertion hole, with a seat being provided at a predetermined position in the insertion hole such that the inserted stop protrusion is seated in and locked to the seat.  
     
     
         8 . The sit-up board according to  claim 1 , wherein each of the first and second boards comprises a plurality of parts, the parts being coupled to each other via coupling rods.  
     
     
         9 . The sit-up board according to  claim 1 , wherein the guide units comprise: a first guide part installed to be aligned with the elastic member; and a second guide part provided outside the first guide part, and perpendicularly changing a direction of the extension cable coupled to the lower end of the elastic member, wherein the first guide part comprises: guide plates supported by at least one support post; and a guide rod rotatably installed between the guide plates, and guiding the extension cable, and the second guide part comprises: a pair of first guide rods rotatably installed between left and right guide plates; and a pair of second guide rods rotatably installed between front and rear guide plates, and arranged to be perpendicular to the first guide rods.  
     
     
         10 . The sit-up board according to  claim 1 , wherein the extension cable of the first board is provided with at least one stop protrusion such that a handle is detachably coupled to the extension cable, and an insertion hole is formed at a predetermined position on the handle such that the stop protrusion provided at each of the ends of the extension cable is inserted into the insertion hole, the insertion hole having a cross shape and being formed such that a central portion thereof is wide to allow the stop protrusion to be easily inserted into the insertion hole, and a side portion thereof is narrow to allow the inserted stop protrusion to be seated in and locked to the insertion hole.  
     
     
         11 . The sit-up board according to  claim 1 , further comprising: one or more pairs of foot supports detachably secured to the first board.