Patent ID: 9657875
Date: 2017-05-23
CPC Classifications: F16L

Claim:
1. A back ferrule, the back ferrule ( 40 ) being used, for pipe connection, along with: a connector body ( 10 ) mounted on an outer circumferential surface of a pipe, with an external thread formed on an outer circumferential surface of the connector body ( 10 ); a drive nut ( 20 ) having an internal thread on an inner circumferential surface thereof; and a front ferrule ( 30 ), the back ferrule ( a nose part ( a tail part ( an outer circumferential surface ( a bellows-shaped elastic part comprising an outer circumferential corrugated surface ( wherein each of the outer circumferential corrugated surface and the inner circumferential corrugated surface comprises a plurality of valleys and a plurality of ridges, and numbers of valleys and ridges of the inner circumferential corrugated surface are larger than numbers of valleys and ridges of the outer circumferential corrugated surface.