Hinge joint between parallel bars - comprises end plates fixed to one bar with collars fitting inside other bar

摘要

The hinge joint is between two bars of the same length and parallel to each other, such as the horizontal cross-bars of two yokes, which together form a folding trestle. A transverse plate (6, 7) is fixed to each end of one bar (4), and has a cylindrical collar (11) pressed out of it, by which it engages in the tubular end of the other bar (5). It can also have a further collar by which it fits into the similar end of the first bar, and can protrude upwards far enough to form a side stop for a plank etc. supported on the trestle.