Rebar coupler

Abstract

Proposed is a rebar coupler including a housing formed by coupling a pair of housing bodies to each other and a plurality of coupling pieces positioned inside the housing and configured to fasten a rebar. The coupling piece includes an outer surface having a first protruding region, a second protruding region, and a first concaved region, and includes an inner surface having serrated protrusions configured to prevent the rebars from being moved in an opposite direction of an insertion direction. The housing body has concaved spaces such that symmetrical hollows are formed at the opposite sides of the housing, and rebar inlet ports are formed at opposite ends of the housing. A pair of the coupling pieces is positioned at the hollows such that the inner surfaces of the coupling pieces face each other, and the first end portions of the coupling pieces are configured to fasten the rebars.

What is claimed is: 
     
         1 . A rebar coupler comprising:
 a housing formed by coupling a pair of housing bodies to each other; and   a plurality of coupling pieces positioned inside the housing and configured to fasten rebars to each other,   wherein each of the coupling pieces comprises:   an outer surface in which a first protruding region and a second protruding region are provided by being arranged in a direction from a first end portion to a second end portion of the coupling piece, with a first concaved region formed between the first and second protruding regions; and   an inner surface provided with serrated protrusions such that an associated rebar inserted into the housing from the first end portion of the coupling piece is prevented from being moved in a direction opposite to an insertion direction of the rebar,   wherein each of the housing bodies is provided with concaved spaces that are respectively positioned at opposite sides of the housing body from a center of a longitudinal direction of the housing body such that hollows symmetrical to each other with respect to the center of the longitudinal direction of the housing body are respectively formed at the opposite sides of the housing, and rebar inlet ports are respectively formed at opposite end portions of the housing, and   a pair of the coupling pieces is positioned at each of the hollows such that the inner surfaces of the coupling pieces face each other, and the first end portions of the coupling pieces are positioned at inner sides of the rebar inlet ports of the housing such that the rebars inserted into the housing are fastened.   
     
     
         2 . The rebar coupler of  claim 1 , wherein each of the housing bodies comprises a pair of first steps positioned at the opposite sides of the housing body from the center of the longitudinal direction of the housing body, the pair of first steps being configured such that end portions of the rebars inserted into the housing from the respective rebar inlet ports positioned at the opposite end portions of the housing are in contact with and are seated on the pair of first steps. 
     
     
         3 . The rebar coupler of  claim 2 , wherein each of the housing bodies comprises:
 a pair of second steps respectively provided along directions from the first steps toward the rebar inlet ports at the opposite end portions of the housing; and   springs respectively interposed between the second end portions of the coupling pieces and the second steps.   
     
     
         4 . The rebar coupler of  claim 3 , wherein each of the housing bodies is provided with opening portions where the respective springs are partially exposed, the opening portions being configured such that respective end portions of the second steps become respective first side surfaces of the opening portions. 
     
     
         5 . The rebar coupler of  claim 1 , wherein each of the housing bodies is configured such that an inner portion thereof is provided with coupling piece seating portions that are formed in shapes corresponding to the outer surfaces of the coupling pieces, and the first end portions of the coupling pieces are respectively positioned on the coupling piece seating portions and are respectively arranged in directions toward the rebar inlet ports of the housing. 
     
     
         6 . The rebar coupler of  claim 1 , wherein when each of the coupling pieces is viewed in cross-section, from the first end portion of the coupling piece to the second end portion of the coupling piece, the first protruding region is provided with a first inclined portion having a predetermined angle in an outside direction, a first horizontal portion extending from the first inclined portion in a horizontal direction, and a second inclined portion extending from the first horizontal portion and having a predetermined angle in an inside direction. 
     
     
         7 . The rebar coupler of  claim 6 , wherein each of the housing bodies is configured such that third steps are respectively provided at the inner sides of the rebar inlet ports, and a space where the first inclined portion of the coupling piece and an associated third step are not engaged with each other when the first end portion of the coupling piece and the third step are in contact with each other is formed between the first inclined portion of the coupling piece and the third step. 
     
     
         8 . The rebar coupler of  claim 6 , wherein when an angle between the first inclined portion and an extending line directing toward a first end portion of the horizontal portion is referred to as θ, a horizontal length of the first inclined portion is referred to as a, and a height of each of the serrated protrusions of the inner surface of the coupling piece is referred to as n, the first inclined portion of the coupling piece and the serrated protrusions of the inner side of the coupling piece satisfy a relational expression 1 that is described below.
     a ×tan θ≥1.1 ×n    Relational expression (1)
 
 
     
     
         9 . The rebar coupler of  claim 6 , wherein the second protruding region is configured to have a third inclined portion having a predetermined angle in the outside direction toward the second end portion of the coupling piece, and a second horizontal portion extending from the third inclined portion in the horizontal direction. 
     
     
         10 . The rebar coupler of  claim 9 , wherein the rebar coupler satisfies a relational expression 1 that is described below.
     a ×tan θ≥1.1 ×n    Relational expression (1)
   where n is a height of each of the serrated protrusions and a is a largest value among a horizontal length of the first inclined portion, a horizontal length of the third inclined portion, and a horizontal length of an inclined portion of a wall surface of a coupling piece seating portion corresponding to the third inclined portion.   
     
     
         11 . The rebar coupler of  claim 9 , wherein when a horizontal length of the first inclined portion is referred to as a, a sum of a length of the first horizontal portion and half of a horizontal length of the second inclined portion is referred to as b, a sum of half of the horizontal length of the second inclined portion and a length of the first concaved region is referred to as c, a horizontal length of the third inclined portion is referred to as a′, and a length of the second horizontal portion is referred to as b′, the protruding regions and the first concaved region of each of the coupling pieces satisfy a relational expression 2 that is described below.
     a+a′> 0.1( b+c+b′ )   Relational expression (2)