Patent ID: 8573425

Claim:
A detachable coupling apparatus for a midsection of a separable bottle, wherein the midsection of the bottle comprising an upper body and a lower body is configured to enable detachable coupling, the midsection serving as a coupling portion between the upper body and the lower body being provided with a watertight member for maintaining water-tightness, the upper body and the lower body having on respective ends thereof upper and lower watertight support portions that are in close contact with respective upper and lower surfaces of the watertight member; the upper body has a plurality of upper locking portions protruding inwards on a lower end of an upright flange that extends from the upper watertight support portion through a first flange, and the lower body has on an upper end thereof a plurality of lower locking portions protruding outwards, thus causing the upper and lower bodies to be detachably coupled to each other as the upper and lower bodies rotate in opposite directions; the upper and lower locking portions are formed to be inclined in a coupling direction thereof, at least either of the upper and lower locking portions have a first sloping surface inclined in a direction in which the watertight member is compressed to a predetermined extent in an initial coupling section of the upper and lower locking portions and a second sloping surface inclined in a direction in which the compressed watertight member is restored to a predetermined extent as coupling of the upper and lower locking portions is further progressed; wherein the first sloping surface is in continuity with the second sloping surface; wherein the first sloping surface begins with a first bottom point and is inclined upwardly from the first bottom point to a top point where the first sloping surface meets the second sloping surface, and the second sloping surface is inclined downwardly from the top point to a second bottom point; and wherein the top point is positioned to be higher than the first and the second bottom points, and the second bottom point is positioned to be higher than the first bottom point.