Patent ID: 6851245

Claim:
A mortar grouting type joint for reinforcing bars, comprising: a hollow cylindrical body defining a longitudinal central axis and having an opening cover ( 2 ) at first and second ends thereof, a bolt hole ( 8 ) on the side wall, and a first supporting protrusion ( 5 ) and a second supporting protrusion ( 5 ) at first and second respective axial positions on an inner peripheral wall, said supporting protrusions extending in a direction substantially parallel to said axis, each being adapted to support a reinforcing bar inserted through one of said opening covers, wherein the portion of the inner peripheral wall between the first and second supporting protrusions is substantially linear; each supporting protrusion ( 5 ) consists of a pair of thin-walled members, wherein the contact points of each of said thin-walled members with said peripheral wall define substantially parallel lines; and said thin-walled members each have a ridge line ( 7 ) sloping relative to the peripheral inner wall, with the portion of each thin-walled member adapted for supporting the reinforcing bar ( 12 ) inserted through the opening cover ( 2 ) constituting the apex; wherein said mortar grouting type joint defines an unobstructed space extending between the opening covers and aligned with said central axis, said space having a diameter at all points along a length of said joint that is equal to at least twice a distance between said central axis and apexes of said thin walled members.