Nodal shutter bar join uses center nodal cross linking bars so opposing bars are co-planar and turn around center cross axis for arrestable linking by round bars at ends

摘要

The join (1000) of the four bars (1-4) with center nodal cross (100) is used to lock first and second bars non-twistably together (5,6). Arrestable joints are fixed to the ends of both bars to lock arrestably relative the center cross at right angle to the respective bar axis. Opposing bar bodies (26,27 and 28,29) lie in the same plane so their section axes in the frame surface can be turned round the center cross axis plane. Each end of the bars has a fork piece (200) rotatable round the cross axis so that opposing bars lie in the same plane and are fixed here by round bars.