Patent attributes
A coupling device for coupling a first casing and a second casing in a movable manner, comprising a first coupling member provided at the first casing, a second coupling member provided at the second casing, and coupled to the first coupling member in such a way that the first casing and the second casing move relative to each other, and a cleaning mechanism that cleans a clearance between the first casing and the second casing or the second coupling member. The cleaning mechanism has a wiper blade that moves in the clearance with movement of the casings, air injection means that injects air to the clearance, and/or a hinge cover that is displaceable within the clearance.