| 摘要 |
<p>The adjustable jig is used in the fabrication of rectangular section duct for heating and ventilating purposes and out of semi-rigid cut and grooved sheets. It comprises a rectangular section trough formed by two parallel vertical panels (1,2) mounted on a work top (4) with one panel (2) hinged (9,10) to pivot towards the exterior. The width between the panels equals one of the transverse duct dimensions. The panels may be adjustable for height using demountable and adjustable head rails (7,12). The pivotable panel (2) may use hinge fittings of which the fixed plates (10) are demountably fixed to the work top (4) by butterfly nuts and bolts (15), with alternative bolt-holes (14) in the top providing for lateral panel adjustment. An elbow-joined stay (17) may be used to prop the panel in the vertical position.</p> |
