| 摘要 |
<p>The shutter folds back like a concertina and can be used for either doors or windows. It comprises a number of flat members separated by intermediary jointing members whose width is twice the thickness of the flat members. The flat and jointing members are hinged together along their lateral edges. One in two of the jointing members is attached to support/guide runners. Two concentric endless chains are located inside the sections which form the frame of the shutter. At each corner of the frame, these chains pass over two free wheels one wheel being located in a corner to activate the chains which in their turn activate the shutter panels during opening/closing.</p> |
