Coupling for mitred limbs on door frame - coupling plates on upper horizontal frame limbs project into mitre region

摘要

The coupling plates (3, 4) are formed as hinge buts whereby the plates of the horizontal and the vertical frame limbs (2) have engaging hinge tongues (5) and tongue recesses which form a press fit when the frame limbs are located in their final assembled position at right angles to one another. The hinge tongues have a curved back (7) corresponding in curvature to the pivot radius (r) while the tongue recesses (6) have a correspondingly shaped back guide (8). The hinge tongues are constructed as flexible projections and in each case pass over locking projection (9) on the tongue recess when the frame limb is swung into position.