Kubota Corporation

Takashi Yokomizo

Shozo Kishi

Kohei Ikeda

Takaaki Kagawa

Yoshinori Itani

Shogo Kaneko

Toshio Toshima

Takahiro Ishihara

Takeshi Hara

An annular sealing material seals a pipe joint between a socket and a spigot. The sealing material includes a bulb part which is composed of a first bulb, a second bulb located closer to the inner side of the socket than the first bulb, and a narrow part present between the first and second bulbs. The first bulb is pressed against the inner circumferential surface of the socket. The second bulb is pressed against the outer peripheral surface of the spigot. The second bulb is inclined towards the pipe center from the first bulb in a natural state before it is provided between the socket and the spigot. The inner diameter of the second bulb is smaller than the outer diameter of the spigot in the natural state. The second bulb is extensible in the pipe diameter direction due to elastic deformation of the narrow part.

Pipe joint

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.

Pipe joint with earthquake-proof function

A separation preventive pipe joint is provided. A locking ring provided on an inner periphery of a socket is engaged with a projection formed on an outer periphery of an end portion of a spigot to prevent the spigot from being separated from the socket. When the spigot is to move deeper in the socket, a sleeve provided inside the socket abuts the end of the spigot to prevent the movement of the spigot. The movement of the spigot may otherwise be prevented by locating a deeper end face of the socket adjacent to the projection of the spigot. The projection fills up a clearance between the outer periphery of the spigot and the inner periphery of an open end portion of the socket, thereby preventing the spigot and the socket from bending relative to each other. The clearance may otherwise be filled up by means of a ring disposed on the inner periphery of the socket and bolts to be screwed into the socket from the outer periphery thereof to press the ring against the outer periphery of the spigot.

Separation-preventive pipe joint

Growing community of inventors

Hyogo, Japan

Takashi Yokomizo