Patent ID: 7854344

Claim:
A lid ( 200 ) for an airtight container ( 100 ) having an upper open end, the lid comprising: a lid body having a rim part defining a sealing depression ( 230 ) for receiving and for sealing to the upper open end of the container, the rim part having an upper surface and an outer surface ( 202 ) connected to the upper surface to define a rim part corner with the upper surface, the lid body including a plurality of locking flap handles ( 210 ) each connected to the lid body at the rim part corner for rotation of each locking flap handle ( 210 ) between an open position and locked positions with respect to the container ( 100 ), each of the locking flap handles ( 210 ) having a locking protrusion ( 212 ) to be locked to a locking depression ( 110 ) formed in an outer surface of the upper open end of the container ( 100 ) when the locking flap handles are in the locked positions; the locking flap handles each including a film hinge ( 220 ) having an elastic hinge part ( 222 ) connecting each respective locking flap handle ( 210 ) to the rim part corner, and a connection part ( 224 ) connecting the elastic hinge part ( 222 ) to a remainder of the locking flap handle ( 210 ) that has the locking protrusion ( 212 ); the elastic hinge part ( 222 ), when the locking flap handle ( 210 ) is in the open position, having an outer surface that forms a smooth, continuous, curved, uninterrupted and following surface with the upper surface of the rim part without having a stepped portion, the outer surface of the elastic hinge part ( 222 ) with the following upper surface of the rim part together being curved outwards at a single predetermined curvature, the elastic hinge part ( 222 ) having thickness that is at a minimum at the rim part corner, with the thickness of the film hinge ( 220 ) smoothly increasing in the connection part ( 224 ) in a direction toward the locking protrusion ( 212 ); the connection part ( 224 ) for connecting the elastic hinge part ( 222 ) to the remainder of the locking flap handle ( 210 ), extending a predetermined length (L) to disperse an impact generated when the locking flap handle is locked to the container; and wherein, when the locking flap handle ( 210 ) is in the locked position to the container, the elastic hinge part ( 222 ) is folded around an inner corner (IC) of the elastic hinge part that is at the rim part corner, forming a boundary between the elastic hinge part and the lid body, and the elastic hinge part is elastically in contact with the outer surface ( 202 ) of the rim part of the lid body.