Reinforcement bar coupler

Abstract

A reinforcement bar coupler, in which a female thread having an inclined taper plane is formed on the inner surface of a coupler cap, and a clamping spring is inserted into and fastened to the female thread. When a reinforcement bar is inserted into the clamping spring, the clamping spring is closely abutted to the bottom of the female thread and is increased in diameter so that the reinforcement bar slips. With the reinforcement bar being inserted, when an external force is applied in the direction opposite to the direction in which the reinforcement bar is inserted, the clamping spring moves along the inclined taper plane and is decreased in diameter, thereby holding the reinforcement bar. It is therefore possible to easily connect and couple the reinforcement bar with one touch based on a change in the diameter of the clamping spring using a relatively simple configuration.

1 . A reinforcement bar coupler with which a reinforcement bar is connected and fixed, comprising:
 a hollow coupler cap having an open outer end through which the reinforcement bar is to be inserted into the coupler cap;   optionally a base spring fitted into the coupler cap;   a spiral female thread circumferentially recessed on an inner surface of the coupler cap if the base spring is not present or the base spring if the base spring is present, the female thread having an inclined taper plane which is inclined and protrudes from a recessed bottom in a direction toward the outer end; and   a clamping spring having a spiral shape that corresponds to the female thread, the clamping spring made of a material that can be twisted and changed in diameter under an external force and be elastically restored, the clamping spring fitted into and fastened to the female thread, wherein the reinforcement bar has a structure of that, when the reinforcement bar is inserted, the clamping spring is closely abutted to the recessed bottom of the female thread and is unwound so that a diameter thereof is increased so that the reinforcement bar slips, and when an external force in a direction opposite to a direction in which the reinforcement bar is inserted is applied in a state in which the reinforcement bar is inserted, the clamping spring moves in the direction toward the outer end of the coupler cap along the inclined taper plane due to a frictional force exerted onto the reinforcement bar and is wound on the reinforcement bar so that the diameter thereof is gradually decreased, thereby holding the reinforcement bar.   
     
     
         2 . The reinforcement bar coupler according to  claim 1 , wherein the reinforcement bar comprises the base spring, and the female thread is formed on the inner surface of the base spring fitted into the coupler cap, wherein the base spring is spirally wound so as to have an outer diameter corresponding to an inner diameter of the coupler cap, and has bottoms which are formed on an inner surface of the base spring, are spirally wound, and are spirally recessed in a circumferential direction at positions where adjacent joints meet, and inclined taper planes which are inclined and protrude from the recessed bottoms in a direction toward the outer end; and
 the reinforcement bar coupler further comprises an anti-dislodgement unit having a reinforcement bar passage hole in a central portion thereof, the reinforcement bar passage hole having a predetermined diameter through which the reinforcement bar can pass, wherein the anti-dislodgement unit is fastened to the outer end of the coupler cap in order to prevent the base spring from being dislodged in the direction toward the outer end of the coupler cap in a state in which the base spring is fitted into the coupler cap.   
     
     
         3 . The reinforcement bar coupler according to  claim 2 , wherein the base spring has a rounded portion which is roundly machined along each corner of upper edges of the joints such that, when the clamping spring is moved in the direction toward the outer end of the coupler cap along the inclined taper plane, an upper edge of each of the joints overlaps an inner portion of a lower edge of an adjacent joint, and an inner diameter of the base spring is decreased under an external force. 
     
     
         4 . The reinforcement bar coupler according to  claim 1 , wherein the clamping spring has clamping taper planes, which correspond to the inclined taper planes such that the clamping spring is slideable and movable along the inclined taper plane, and an angled corner portion, a part of which thrusts into the reinforcement bar when the diameter of the clamping spring is decreased. 
     
     
         5 . The reinforcement bar coupler according to  claim 1 , further comprising a hook portion, a support plate, and a leaf spring, which prevent the clamping spring from interfering with insertion of the reinforcement bar while the reinforcement bar is being inserted into the coupler cap, and causes the clamping spring to hold the reinforcement bar when the insertion of the reinforcement bar into the coupler cap is completed; and
 wherein the hook portion is provided adjacent to the outer end of the coupler cap, the hook portion supporting one end of the clamping spring;   the support plate is provided inside the coupler cap; and   the leaf spring is supported by the support plate, the leaf spring having a protrusion protruding from the support plate between the hook portion and the leaf spring such that the other end of the clamping spring is supported in a state in which the clamping spring is twisted in a direction in which the diameter there is increased, wherein, when the reinforcement bar is inserted into the coupler cap and presses against the protrusion, the protrusion is recessed due to elasticity and no longer supports the other end of the clamping spring, so that the diameter of the clamping spring is restored due to elasticity.   
     
     
         6 . The reinforcement bar coupler according to  claim 2 , wherein the clamping spring has clamping taper planes, which correspond to the inclined taper planes such that the clamping spring is slideable and movable along the inclined taper plane, and an angled corner portion, a part of which thrusts into the reinforcement bar when the diameter of the clamping spring is decreased. 
     
     
         7 . The reinforcement bar coupler according to  claim 2 , further comprising a hook portion, a support plate, and a leaf spring, which prevent the clamping spring from interfering with insertion of the reinforcement bar while the reinforcement bar is being inserted into the coupler cap, and causes the clamping spring to hold the reinforcement bar when the insertion of the reinforcement bar into the coupler cap is completed; and
 wherein the hook portion is provided adjacent to the outer end of the coupler cap, the hook portion supporting one end of the clamping spring;   the support plate is provided inside the coupler cap; and   the leaf spring is supported by the support plate, the leaf spring having a protrusion protruding from the support plate between the hook portion and the leaf spring such that the other end of the clamping spring is supported in a state in which the clamping spring is twisted in a direction in which the diameter there is increased, wherein, when the reinforcement bar is inserted into the coupler cap and presses against the protrusion, the protrusion is recessed due to elasticity and no longer supports the other end of the clamping spring, so that the diameter of the clamping spring is restored due to elasticity.   
     
     
         8 . The reinforcement bar coupler according to  claim 3 , wherein the clamping spring has clamping taper planes, which correspond to the inclined taper planes such that the clamping spring is slideable and movable along the inclined taper plane, and an angled corner portion, a part of which thrusts into the reinforcement bar when the diameter of the clamping spring is decreased. 
     
     
         9 . The reinforcement bar coupler according to  claim 3 , further comprising a hook portion, a support plate, and a leaf spring, which prevent the clamping spring from interfering with insertion of the reinforcement bar while the reinforcement bar is being inserted into the coupler cap, and causes the clamping spring to hold the reinforcement bar when the insertion of the reinforcement bar into the coupler cap is completed; and
 wherein the hook portion is provided adjacent to the outer end of the coupler cap, the hook portion supporting one end of the clamping spring;   the support plate is provided inside the coupler cap; and   the leaf spring is supported by the support plate, the leaf spring having a protrusion protruding from the support plate between the hook portion and the leaf spring such that the other end of the clamping spring is supported in a state in which the clamping spring is twisted in a direction in which the diameter there is increased, wherein, when the reinforcement bar is inserted into the coupler cap and presses against the protrusion, the protrusion is recessed due to elasticity and no longer supports the other end of the clamping spring, so that the diameter of the clamping spring is restored due to elasticity.   
     
     
         10 . The reinforcement bar coupler according to  claim 1 , wherein the female thread is formed directly on the inner surface of the coupler cap. 
     
     
         11 . The reinforcement bar coupler according to  claim 10 , wherein the clamping spring has clamping taper planes, which correspond to the inclined taper planes such that the clamping spring is slideable and movable along the inclined taper plane, and an angled corner portion, a part of which thrusts into the reinforcement bar when the diameter of the clamping spring is decreased. 
     
     
         12 . The reinforcement bar coupler according to  claim 10 , further comprising a hook portion, a support plate, and a leaf spring, which prevent the clamping spring from interfering with insertion of the reinforcement bar while the reinforcement bar is being inserted into the coupler cap, and causes the clamping spring to hold the reinforcement bar when the insertion of the reinforcement bar into the coupler cap is completed; and
 wherein the hook portion is provided adjacent to the outer end of the coupler cap, the hook portion supporting one end of the clamping spring;   the support plate is provided inside the coupler cap; and   the leaf spring is supported by the support plate, the leaf spring having a protrusion protruding from the support plate between the hook portion and the leaf spring such that the other end of the clamping spring is supported in a state in which the clamping spring is twisted in a direction in which the diameter there is increased, wherein, when the reinforcement bar is inserted into the coupler cap and presses against the protrusion, the protrusion is recessed due to elasticity and no longer supports the other end of the clamping spring, so that the diameter of the clamping spring is restored due to elasticity.   
     
     
         13 . A reinforcement bar coupler with which a reinforcement bar is connected and fixed, comprising:
 a hollow coupler cap having an open outer end through which the reinforcement bar is to be inserted into the coupler cap, the coupler cap having a spiral female thread circumferentially recessed on an inner surface of the coupler cap, the female thread having an inclined taper plane which is inclined and protrudes from a recessed bottom in a direction toward the outer end; and   a clamping spring having a spiral shape that corresponds to the female thread, the clamping spring made of a material that can be twisted and changed in diameter under an external force and be elastically restored, the clamping spring fitted into and fastened to the female thread, wherein the reinforcement bar has a structure of that, when the reinforcement bar is inserted, the clamping spring is closely abutted to the recessed bottom of the female thread and is unwound so that a diameter thereof is increased so that the reinforcement bar slips, and when an external force in a direction opposite to a direction in which the reinforcement bar is inserted is applied in a state in which the reinforcement bar is inserted, the clamping spring moves in the direction toward the outer end of the coupler cap along the inclined taper plane due to a frictional force exerted onto the reinforcement bar and is wound on the reinforcement bar so that the diameter thereof is gradually decreased, thereby holding the reinforcement bar, wherein the clamping spring has clamping taper planes, which correspond to the inclined taper planes such that the clamping spring is slideable and movable along the inclined taper plane, and an angled corner portion, a part of which thrusts into the reinforcement bar when the diameter of the clamping spring is decreased.   
     
     
         14 . The reinforcement bar coupler according to  claim 13 , further comprising a hook portion, a support plate, and a leaf spring, which prevent the clamping spring from interfering with insertion of the reinforcement bar while the reinforcement bar is being inserted into the coupler cap, and causes the clamping spring to hold the reinforcement bar when the insertion of the reinforcement bar into the coupler cap is completed; and
 wherein the hook portion is provided adjacent to the outer end of the coupler cap, the hook portion supporting one end of the clamping spring;   the support plate is provided inside the coupler cap; and   the leaf spring is supported by the support plate, the leaf spring having a protrusion protruding from the support plate between the hook portion and the leaf spring such that the other end of the clamping spring is supported in a state in which the clamping spring is twisted in a direction in which the diameter there is increased, wherein, when the reinforcement bar is inserted into the coupler cap and presses against the protrusion, the protrusion is recessed due to elasticity and no longer supports the other end of the clamping spring, so that the diameter of the clamping spring is restored due to elasticity.   
     
     
         15 . A reinforcement bar coupler with which a reinforcement bar is connected and fixed, comprising:
 a hollow coupler cap having an open outer end through which the reinforcement bar is to be inserted into the coupler cap;   a base spring fitted into the coupler cap, the base spring having an inner surface on which a female thread is formed, the female thread having an inclined taper plane which is inclined and protrudes from a recessed bottom in a direction toward the outer end, wherein the base spring is spirally wound so as to have an outer diameter corresponding to an inner diameter of the coupler cap, and has bottoms which are formed on an inner surface of the base spring, are spirally wound, and are spirally recessed in a circumferential direction at positions where adjacent joints meet, and inclined taper planes which are inclined and protrude from the recessed bottoms in a direction toward the outer end   a clamping spring having a spiral shape that corresponds to the female thread, the clamping spring made of a material that can be twisted and changed in diameter under an external force and be elastically restored, the clamping spring fitted into and fastened to the female thread, wherein the reinforcement bar has a structure of that, when the reinforcement bar is inserted, the clamping spring is closely abutted to the recessed bottom of the female thread and is unwound so that a diameter thereof is increased so that the reinforcement bar slips, and when an external force in a direction opposite to a direction in which the reinforcement bar is inserted is applied in a state in which the reinforcement bar is inserted, the clamping spring moves in the direction toward the outer end of the coupler cap along the inclined taper plane due to a frictional force exerted onto the reinforcement bar and is wound on the reinforcement bar so that the diameter thereof is gradually decreased, thereby holding the reinforcement bar.   
     
     
         16 . The reinforcement bar coupler according to  claim 15 , wherein the base spring has a rounded portion which is roundly machined along each corner of upper edges of the joints such that, when the clamping spring is moved in the direction toward the outer end of the coupler cap along the inclined taper plane, an upper edge of each of the joints overlaps an inner portion of a lower edge of an adjacent joint, and an inner diameter of the base spring is decreased under an external force. 
     
     
         17 . The reinforcement bar coupler according to  claim 16 , further comprising an anti-dislodgement unit having a reinforcement bar passage hole in a central portion thereof, the reinforcement bar passage hole having a predetermined diameter through which the reinforcement bar can pass, wherein the anti-dislodgement unit is fastened to the outer end of the coupler cap in order to prevent the base spring from being dislodged in the direction toward the outer end of the coupler cap in a state in which the base spring is fitted into the coupler cap. 
     
     
         18 . The reinforcement bar coupler according to  claim 15 , further comprising a hook portion, a support plate, and a leaf spring, which prevent the clamping spring from interfering with insertion of the reinforcement bar while the reinforcement bar is being inserted into the coupler cap, and causes the clamping spring to hold the reinforcement bar when the insertion of the reinforcement bar into the coupler cap is completed; and
 wherein the hook portion is provided adjacent to the outer end of the coupler cap, the hook portion supporting one end of the clamping spring;   the support plate is provided inside the coupler cap; and   the leaf spring is supported by the support plate, the leaf spring having a protrusion protruding from the support plate between the hook portion and the leaf spring such that the other end of the clamping spring is supported in a state in which the clamping spring is twisted in a direction in which the diameter there is increased, wherein, when the reinforcement bar is inserted into the coupler cap and presses against the protrusion, the protrusion is recessed due to elasticity and no longer supports the other end of the clamping spring, so that the diameter of the clamping spring is restored due to elasticity.