Coupling

A coupling for securing together two parts comprising a first member defining a cylindrical spigot having a fist pair of spaced cylindrical locating surfaces and a first radially extending thrust face, and a second member defining a second radially extending thrust face and also a spigot bore in which the spigot locates, the spigot bore having a second pair of locating surfaces complementary to the first pair of locating surfaces, said first and second pairs of locating surfaces engaging with each other when the spigot is located in the spigot bore to provide radial location of the first and second members and means operable to move the members relative to each other so that the thrust faces are urged into engagement with each other, said means comprising a further bore formed in the second member, said further bore extending parallel to a tangent to the spigot bore, an angularly adjustable member mounted in the further bore and movable about the axis of the further bore, a first thrust surface defined on the spigot, a second thrust surface defined on the angularly adjustable member for engagement with the first thrust surface when the spigot is located in the spigot bore, said thrust surfaces, when the angularly adjustable member is moved about the axis of the further bore, cooperating to produce an axial thrust which urges said thrust faces into engagement with each other.