| 摘要 |
<p>A hinge (11) for fireproof doors associated with a second hinge (10) which automatically closes fireproof doors by means of a torsion spring, wherein the hinge (11) comprises a frame- side portion and a door- side portion, equipped with respective tubular sections which, aligned with each other, define a housing seat of a hinging group which comprises a cam force regulator group (23, 31, 50, 57). The cam force regulator group comprises a cam block (50) facing a ball -holder body (57) which houses a pair of balls (54), the cam block (50) comprising a surface facing the balls (54) provided with a double half-groove (53). Each half -groove (53) comprises a first portion ascending towards an apex (55) for a first angle and a second portion descending from the apex for a second angle, the angles extending for a total of 180° so that, in a return phase of the door, the loading of the spring (61) is opposed to the return force of the torsion spring of the second hinge (10) along the second angle and is added to said return force along the remaining first angle).</p> |
