US Patent 7331567 Coupling device for two connecting poles

A coupling device for two connecting poles which includes: a lower fixing sleeve sleeved on the upper portion of a lower connecting pole, having an opening communicating the outer surface and the inner surface of the lower fixing sleeve, two fixed plates extend outwards from the edge of the opening; an upper fixing sleeve having a through gap, two fixing plates extend outwards from the gap, the fixing plates of the upper fixing sleeve are disposed within the lower fixing sleeve, the fixing plates including releasing portions and locking portions; a controlling member rotatably connected to the lower fixing sleeve, including a central portion and two side portions, the inner side surfaces of the two side portions contacting the outer side surfaces of the two releasing portions.