Patent ID: 7571939

Claim:
A pipe joint comprising: a socket substantially in a tubular shape; a plug substantially in a tubular shape and inserted into an inserting port of the socket; a retaining unit for preventing the plug from being drawn out from the socket; a seal ring arranged at an inner periphery of the socket for sealing the inner periphery of the socket and an outer periphery of the plug; and a hold ring arranged at the inner periphery of the socket for hampering the seal ring from being moved, said hold ring comprising: a notched portion provided on the hold ring, the notched portion being fitted with a projected portion formed at a position of the inner periphery of the socket for attaching the hold ring; and a projected portion projected in a direction of the inserting port; and the plug includes a ring-shaped projected portion for engaging with the retaining unit, and a recess portion provided in the ring-shaped projected portion or a flat portion provided on the ring-shaped projected portion to be engaged with the projected portion of the hold ring, wherein the seal ring is disposed in a rear portion of the socket, the retaining unit is disposed adjacent to said seal ring at a position closer to a front portion of the socket, and the hold ring is disposed between the seal ring and the retaining unit, wherein the ring-shaped projected portion includes a taper portion, wherein a diameter of the taper portion becomes smaller along an insertion direction of the taper portion, and a face on a side of a pipe connecting portion contiguous to the taper portion, said face being substantially orthogonal to an axis of said taper portion, and wherein the projected portion of the hold ring is engaged with the recess portion or a flat portion provided at the ring-shaped projected portion from a side of the taper portion of the ring-shaped projected portion.