Patent ID: 7798537

Claim:
A coupling apparatus comprising: an annular coupling body having a proximal end part attached to a predetermined part of an object to be connected and a distal end part positioned opposite the proximal end part; plural fitting projections projecting along an axial direction of the coupling body from plural predetermined circumferential positions on the distal end part of the coupling body, each fitting projection having an engaging hook projecting in one predetermined circumferential direction at a projecting end part thereof, and the plural fitting projections being formed in plural blocks, each having the predetermined number of fitting projections and being independent of the coupling body; and a fixing structure which is independent of the coupling body and the projection blocks and which detachably fixes the projection blocks to the predetermined circumferential positions on the distal end part of the coupling body, the fixing structure including insert connection members each of which has a bolt with a head, which is inserted in a through hole formed in at least one of the coupling body and each block and which is detachably connected to the other, wherein the coupling apparatus is structured such that two of the coupling apparatuses approach each other coaxially to fit the fitting projections of one coupling apparatus into fitting recesses between the fitting projections of the other coupling apparatus, and subsequently, the coupling body of the one coupling apparatus is rotated in a predetermined circumferential direction relative to the coupling body of the other coupling apparatus to make the engaging hooks of the fitting projections of the one coupling apparatus engage with the engaging hooks of the fitting projections of the other coupling apparatus, thus detachably connecting the two coupling apparatuses to each other.