A spigot is inserted into a socket, with a seal packing pressed from the opening side of the socket into an annular space defined between the socket and the spigot, a lock ring fitted in an annular groove formed in the inner peripheral surface of the pocket inwardly of the seal packing, and an engaging projection provided on the outer periphery of the front end of the spigot for axial engagement with the lock ring. The lock ring is a split lock ring which can be inserted from the annular space between the socket and the spigot toward the innermost part of the socket and has a diametrically expanding force. The depth of the annular groove is controlled so as to allow the radially inner region of the lock ring fitted in the groove to engage the engaging projection. A back-up ring is disposed between the seal packing and the split lock ring and the mutual abutting surfaces of the split lock ring and back-up ring are conical surfaces tapering toward the front end of the spigot.
A separation preventive pipe joint is provided, in which a locking ring is held by an elastic ring with its axis centered in a locking ring receiving groove. An outer peripheral projection is formed on an end portion of the spigot, the outer peripheral projection being engageable with the locking ring from a location deeper than the locking ring. An inner peripheral projection is formed in an inner peripheral portion of the socket which is located deeper than the locking ring receiving groove for backing up the locking ring. A first inner peripheral surface having a larger diameter than the inner peripheral projection is formed in an inner peripheral portion of the socket which is located deeper than the inner peripheral projection. A second inner peripheral surface is formed between the first inner peripheral surface and the inner peripheral projection, the second inner peripheral surface being larger than the inner peripheral projection and smaller than the first inner peripheral surface in diameter.
6203073 - Tube joint - Owned by Waterworks Technology Development Organization Co., Ltd. (Osaka,JP)
A tube joint comprises: a pushing ring provided at its outer periphery with a projection and fitted to an outer periphery of one end of a joint tube; a tube or a joint body provided at is side opposed to the pushing ring with a projection opposed to the projection of the pushing ring, the tube or the joint body having a receiving portion which is widened toward the pushing ring and the tube or the joint body being fitted to an outer periphery of the joint tube with a peripheral gap left therebetween; a fastening tool capable of moving the pushing ring in a direction of the tube or the joint body; a packing provided between inner and outer side of the tube or the joint body and the joint tube, and fitted through the receiving portion by its own resilient deformation by operation of the fastening tool; and a spacer inserted between the pushing ring and the tube or the joint body to limit a distance between the pushing ring and the tube or the joint body to a constant value.
A pipe joint structure is disclosed. An inscribing joint pipe 2 is fixed to an inner peripheral surface at an end portion of a first pipe 1a, while being projected slightly outwardly from the axial end of the pipe 1a. A stopper ring 15 is fixed onto the outer peripheral surface of the pipe 1a at a location slightly spaced from the axial end thereof. An annular engaging notch 11 is formed in the outer peripheral surface near the stopper ring or an annular engaging ring 11' is inserted around the end portion of the pipe 1a and fixed near the stopper ring. A circumscribing reinforcing pipe 3a, 3b are fixed to an outer peripheral surface at an end portion of the other pipe 1b to be joined to the pipe 1a, while being projected slightly outwardly from the axial end of the pipe 1b. The circumscribing reinforcing pipe is provided with an engaging ring 10 at its tip end portion to engage the annular engaging ring 11 or a remote end of the annular fitting ring from the other pipe 1b in the state that the pipes 1a and 1b are joined together. Plural projections 4a, 4b are formed on the inner peripheral surface of the other pipe 1b near the axial end of the pipe 1a. A cover tape 9 with a pressure-sensitive adhesive 8 is provided around the outer periphery of the pipe 1a at location from the stopper ring 15 toward the end thereof. A pressure-sensitive adhesive layer 5 and a reinforcing cloth 6 are attached to the inner peripheral surface of the pipe 1b inclusive of the circumscribing reinforcing pipe 3a, 3b from the engaging ring 10 at the circumscribing reinforcing pipe 3a, 3b. The reinforcing cloth 6 is impregnated with a lubricant having plasticity to the pressure-sensitive adhesive. When the pipe is joined, the adhesive layer 5 and the reinforcing layer 6 are interposed between joining surfaces of the pipe 1a, 1b joined through the circumscribing reinforcing pipe 3a, 3b and the inscribing joining pipe 2.
A pipe joint with earthquake-proof function is provided. A lock ring engages with an accommodating groove of a socket. A tapered surface converging toward the opening side of the socket is formed on at least one of a portion of the lock ring engaging the accommodating groove and a portion of the accommodating groove engaging the lock ring. When a disengagement prevention force in a pipe axial direction for preventing a spigot from being disengaged from the socket by the engagement is transmitted from an accommodating groove to the lock ring through the tapered surface, a line of action of a component force of the disengagement prevention force in a direction perpendicular to the tapered surface passes the opening side of the socket of a contacting point between a socket bottom end part of the lock ring and the outer periphery of the spigot along the outer surface of the spigot.
A pipe connecting apparatus for connecting a first pipe with a second pipe inserted into the first pipe member is disclosed. The apparatus includes an elastic seal to be disposed within a gap formed between an inner peripheral face of the first pipe and an outer peripheral face of the second pipe, the elastic seal being compressed in an axial direction along the axis of the first pipe for sealing the gap, a press ring fitted on the second pipe, the press ring being movable on the outer peripheral face of the second pipe in the axial direction, and a retainer member fitted on the second pipe, the retainer member having a locked condition in which the retainer member is pressed against the second pipe and a released condition in which the retainer member is radially expanded to be released from the locked condition, the retainer member being switched over from the released condition to the locked condition in association with a movement thereof relative to the press ring. A sequentially operative mechanism is operative to press the elastic seal alone in the axial direction while the retainer member is at the released condition in a first state where the compressive force is low, the sequentially operative mechanism being operative to allow the retainer member to be switched over to the locked condition in a second state where the compressive force is high.
