US Patent 8726971 Shutter

A shutter (S) including a plurality of support portions (10) provided in array in a sliding direction of the shutter, a hinge portion (20) for connecting adjoining two support portions (10), and slide supporting portions (30) provided at both ends of each support portion (10) so as to face a pair of guiderails. Each slide supporting portion (30) has a pair of first and second abutting portions (32 and 34) formed in array in the sliding direction for slidably engaging with the guiderail. Each support portion (10) is supported by the pair of guiderails at three or more out of a total of four first and second abutting portions (32 and 34) when a load is applied to the shutter from the outside.