| 摘要 |
<p>The invention relates to a system for fastening spark plugs (4) for boilers or the like, comprising a retainer (1) for fastening spark plugs (4) of boilers, with an hole housing the ceramic body (104) of the spark plug (4). According to the invention said hole axially projects for a certain length at least on one side of the retainer (1) such to form a cylindrical housing (5) for the ceramic body (104) of the spark plug (4), a cylindrical tightening ring (6, 8) being provided having such inner and external dimensions that it can be inserted by force fit between the inner wall 15 of the cylindrical housing (5) and the external wall of the ceramic body (104) so to generate a predetermined radial tightening force of the spark plug (4) and such to obtain a tight seal between one side and the other one of the retainer (1). In a first embodiment the ring 20 (6) is made of metal having predetermined ductility and deformation capacity characteristics. In a second embodiment, the ring (8) is made of metal having a low deformation capacity and it has a plurality of openings (108, 9) for releasing the radial deformation of the 25 ring (8) when the spark plug (4) is tightened inside the cylindrical housing (5).</p> |
