Coupling key for connecting fire hoses has several surfaces and back stop and has different standard wrench widths between back stop and surfaces whereby gripping area is provided on the coupling key

摘要

The coupling key has several key surfaces. The back stop (2) is at one end of the key. The wrench width between back stop and surfaces are related in such a manner that between back stop and first key surface (1.1), second key surface (1.2), third key surface (1.3), fourth key surface (1.4) and fifth key surface (1.5), there is definite standard wrench width. The coupling key has a gripping area (3).