To provide a synthetic resin coupling capable of stably displaying an excellent detachment prevention effect without losing a latch effect even when large external force of an extracting direction is applied to a coupling part, displaying its original retractability.
This coupling is an elastic detachment prevention coupling in which a socket 2 and a spigot 1 of a synthetic resin pipe are made to have a seal connecting structure which can be elongated and contracted and a detachment prevention structure is made by a lock ring 8 arranged between a latch surface provided on the inside surface of the socket 2 and a latch projection 3 provided on the outside surface of the spigot 1 at a location which is deeper than this latch surface. The coupling is made to have a structure in which a reinforcing ring 14 made of a nondeformable material with rigidity higher than that of a synthetic resin material constituting the spigot 1 at a location corresponding to the latch projection 3 on the side of the inside surface of the spigot 1 is buried within a spigot pipe and a crack induction of the latch projection 3 is prevented.
YAMADA YOSHIKI
MAKI ATSUSHI
| JPS6168750A |
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